Análisis de la estructura anatómica de la madera y del carbón de dos especies de Sapotaceae

Charcoal is an energetic input much applied in different segments of ironwork, metallurgic, cement industry and others, being important economically and historically in Brazil. One manner of determine the precedence of wood coal is the material identification, what allow to probe the legality of exploration and which is its possible origin. This paper aims to describe wood and charcoal anatomy of Pouteria macrophylla (A.DC.) Eyma and Micropholis guianensis (A.DC) Pierre, and compare the characteristics before and after carbonization process, for the purpose of increase the information about this materials. The samples were carbonized on electric muffle furnace, with maximum temperature of 450 ºC, in approximately 6 hours and 30 minutes. The elevate contraction of cells of Pouteria macrophylla and Micropholis guianensis during carbonization process result in dimensional changes, but it not affect qualitative aspects of anatomical characteristics, being possible the distinction of species and identification of charcoal by wood description.El carbón vegetal es un insumo energético muy utilizado en diversos segmentos de la industria siderúrgica, metalúrgica, cimientos y otras, presentando importancia económica e histórica en Brasil. Una de las formas de determinar la procedencia del carbón vegetal es identificando este material, lo que permite comprobar la legalidad de explotación, y cual es su posible origen. Este trabajo tuvo como objetivo describir la anatomía de la madera y del carbón de Pouteria macrophylla (A.DC.) Eyma y Micropholis guianensis (A.DC) Pierre, y comparar las características antes y después del proceso de carbonización, con la finalidad de suministrar más información sobre la estructura de estos materiales. Los cuerpos de prueba se carbonizaron en horno de mufla, a temperatura máxima de 450 ºC durante un período de aproximadamente 6 horas y 30 minutos. La elevada contracción de las células de Pouteria macrophylla y Micropholis guianensis durante el proceso de carbonización causó alteraciones dimensionales, que no perjudicaron el aspecto cualitativo de las características anatómicas, siendo posible la distinción de especies, e identificación del leño carbonizado a través de la descripción de la madera

Colour responses of Eucalyptus grandis wood to the Brazilian process of thermal modification

A study of colour assessment, using the CIEL*a*b* system, was conducted with samples of Eucalyptus grandis wood thermally treated by the Brazilian industrial process of thermal modification, VAP HolzSysteme®, at three different temperatures, i.e. 140, 160 and 180 °C. Previous to the treatment, the samples were classified into three groups according to their distance to the wood pith, on the radial direction. All thermally modified samples presented a noticeable colour change, confirmed by high values of ΔE*. As the intensity of the treatment increased, the eucalypt samples presented an increase of red colour tone (a*) (up to 160 ºC) and a decrease of colour lightness (L*). Significant colour differences were found among the classified groups, for both untreated and thermally modified samples. The eucalypt samples groups showed different colour responses when thermally treated at 140 and 160 ºC. At 180 ºC the groups didn’t show a significant colour response variation.The authors gratefully acknowledge the financial support of the Brazilian National Council for Scientific and Technological Development (CNPq) through the doctoral grant of Carolina Griebeler by means of the “Ciência sem Fronteiras” program

Influencia de la granulometría de la muestra en la discriminación de especies de "Salix" por infrarrojo cercano

En Brasil, las especies cultivadas del género Salix son de gran importancia en la artesanía, con propiedades diferentes en relación a la maleabilidad y resistencia. Este trabajo tuvo como objetivo aplicar la espectroscopía de infrarrojo cercano (FT-NIR) para la discriminación de cuatro especies de Salix, comparando muestras de materia maciza y partículas. Las muestras de Salix viminalis, Salix x rubens, Salix purpurea y Salix sp., fueron seleccionadas en siete sitios en la región del Valle del Río Canoas, Estado de Santa Catarina (Brasil). Los espectros de absorción se obtuvieron en FT-NIR espectrofotómetro (Bruker Tensor 37). La forma y la granulometría de las muestras de Salix spp. tienen influencia en la discriminación de las especies por FT-NIR. La técnica tuvo mayor capacidad de distinción para la granulometría de menor tamaño.In Brazil, the cultivated species of genus Salix have great importance in crafts, with different properties in relation to malleability and resistance. This paper aimed to apply near infrared spectroscopy (FT-NIR) for discrimination of four Salix species, comparing solid sample and particulate material. Samples from Salix viminalis, Salix x rubens, Salix purpurea and Salix sp. were collected in seven sites in the region of Rio Canoas Valley, Santa Catarina State, Brazil. It was obtained absorbance spectra in FT-NIR (Bruker Tensor 37). The shape and particle size of Salix spp. influenced the discrimination of species by near infrared. The technique had a more efficient distinction for smaller particle size samples

Anatomía y ultraestructura de la madera de tres especies de Prosopis (Leguminosae-Mimosoideae) del Parque Chaqueño seco, Argentina

This study was aimed to contribute to the knowledge of anatomy and ultra structure of the 3 species of wood of Prosopis growing in heterogeneous forest dry Chaqueño Park. The study material was collected in the province of Santiago del Estero northwest Argentina. The species studied were: Prosopis vinalillo, Prosopis alba and Prosopis nigra. The wood of the species was described macroscopically using a magnifying glass. For microscopic study were prepared permanent slides from the three planes of wood and dissociated material to measure the cellular elements. The results show that the 3 species are very similar and consistent with the structural features of the subfamily Mimosoideae. However, the number of vessels/mm2 was quite variable between species and between individuals of the same species. In the cases of intervessel, vessel-ray and vesselparenchyma pits is important to describe its shape, type, distribution and ornamentation. Samples observed under scanning electron microscope allowed displaying ornaments in pits and striations on the vessels walls. These striations were shown to be characteristics of the 3 Prosopis species studied.El presente trabajo fue dirigido para contribuir al conocimiento de la anatomía y ultra estructura de la madera de 3 especies de Prosopis que crecen en formaciones vegetales heterogéneas del Parque Chaqueño seco. El material de estudio fue colectado en la Provincia de Santiago del Estero, noroeste de Argentina. Las especies estudiadas fueron: Prosopis vinalillo, Prosopis alba y Prosopis nigra. La madera de las especies fue descrita macroscópicamente a través de lupa. Para el estudio microscópico se prepararon láminas permanentes de los tres planos de la madera y del material disociado para medir los elementos celulares. Los resultados muestran que las 3 especies presentan gran semejanza estructural y concuerdan con las características generales de la subfamilia Mimosoideae. Sin embargo, el número de vasos/mm2 fue un carácter bastante variable entre las especies y entre individuos de la misma especie. En los casos de las puntuaciones intervasculares, radio-vasculares y parénquimo-vasculares es importante describir su forma, tipo, distribución y ornamentación. Las muestras observadas con microscopio electrónico de barrido permitieron mostrar las ornamentaciones en las puntuaciones y las estriaciones en las paredes de los vasos. Estas estriaciones mostraron ser características de las 3 especies de Prosopis estudiadas

Potential use of nir and visible spectroscopy to analyze chemical properties of thermally treated wood

The modification of wood by thermal treatments produces characteristic changes in its chemical composition and surface color and can improve the structural and esthetic quality. The objective of this paper is to evaluate the potential of near infrared and visible spectroscopy to predict the modifications in chemical composition of Eucalyptys grandis and Pinus taeda after thermal treatment. Near infrared and visible spectra were collected directly on the longitudinal surface of wood samples. The thermally modified wood of both species showed higher content of lignin and extractives than the untreated wood. There was darkening of thermally modified wood, as a result of chemical modification caused by heat. The Near infrared/visible technique identified the groups that were modified by treatment. NIR and visible spectroscopy can be used to predict chemical composition of natural or thermally treated Eucalyptus grandis and Pinus taeda

A contribution to the identification of charcoal origin in Brazil: I- anatomical characterization of corymbia and eucalyptus

Charcoal is one of the main forestry products and Brazil is the world�s largest producer. Its production from native species is estimated at 30-35% of total output. One of the major problems of the iron and steel industry is charcoal consumption, especially in terms of environmental and social aspects. Therefore, the use of reforestation species must be increased. Considering most of the energy forests in Brazil are planted with eucalyptus, the present work aims to contribute to the identification of charcoal origin through anatomical analysis of Eucalyptus and Corymbia. The wood samples were carbonized in a muffle furnace during 7h to a maximum of 450ºC. Anatomical analysis was done according to IAWA Committee. We found few works with charcoal anatomy and the species analyzed were not characterized. The results on charcoal are very close to previous studies of wood anatomy. But, we recommend the comparison of materials of similar features, enhancing the visual acuity, particularities of each material and modifications that might happen. We believe that this analysis is an accurate tool to identify the source of charcoal and can help to guarantee the sustainability of the charcoal supply chain

Estudio de la productividad de corte en madera "Pinus elliotti" utilizando un prototipo de aserradero portátil

El aserrío de trozas en tablas puede agregar valor a la madera producida en pequeñas propiedades rurales. El objetivo de este trabajo fue evaluar la calidad del aserrío de trozas de Pinus elliottii en un prototipo de aserradero portátil construido en cooperación entre una institución de investigación y una empresa privada. En base a los resultados obtenidos aún deberán realizarse algunos ajustes mecánicos en el prototipo. Sin embargo, el rendimiento encontrado fue superior al 71%, la velocidad de alimentación estuvo entre 0,94 y 1,82 m/s, y la productividad máxima en madera aserrada fue de 2,17m3/h, que son valores compatibles o mejores que los modelos similares importados. La variación de espesor máximo quedó por debajo del límite máximo permitido por la norma Brasileña

Wood and charcoal identification of five species from the miscellaneous group known in Brazil as “Angelim” by Near-IR and wood anatomy

Samples of wood sold as “angelim” in Brazil were studied. Disks from the trunks of Diplotropis purpurea, Hymenolobium petraeum, Parkia pendula, Vatairea guianensis and Vatairea paraensis were obtained from Mato Grosso state. Samples from pith to bark of each species were obtained, oriented in the three anatomical planes. Each sample was wrapped in aluminum foil and carbonized in a muffle furnace, with a final temperature of 450 °C and a heating rate of 1,66 °C min-1. The description of the anatomical elements of wood and charcoal samples followed the orientations of the International Association of Wood Anatomists, on the basis of 25 readings regarding frequency and tangential diameter of the vessels and height and width of the rays in micrometers. Infrared analyses were performed with a Bruker Tensor 37 spectrophotometer equipped with an integrating sphere and operating in reflectance mode, with resolution of 4 cm-1 and a spectral range of 10000-4000 cm-1. The wood and charcoal samples were placed on top of integrating sphere and one spectrum was obtained from each surface, resulting in six spectra for each physical sample. The results of anatomical analysis showed that the qualitative characteristics of wood remained in charcoal, so the method can be applied for species discrimination. When comparing cell dimensions, we observed different behavior between species in the same carbonization process in function of cell wall thickness and parenchyma distribution. In infrared analysis, pretreatment influenced adequate discrimination of “angelim” species in wood and charcoal. Linear discriminant analysis based on PCA scores and the region between 4000-6200 cm-1 was more efficient. Near infrared analysis can be used for differentiation of wood and charcoal of “angelim” species

Effect of the Brazilian thermal modification process on the chemical composition of "Eucalyptus grandis juvenile" wood - Part 1: Cell wall polymers and extractives contents

This article reports the first study of the influence of the Brazilian process of thermal modification called VAP HolzSysteme® on the chemical composition of Eucalyptus wood. Flatsawn boards of Eucalyptus grandis juvenile wood were tested for four treatment levels: untreated and thermally modified at final cycle temperatures of 140, 160 and 180 °C. Chemical analyses were carried out according to the standards of the Technical Association of the Pulp and Paper Industry and encompassed total extractives, insoluble lignin, holocellulose (cellulose + hemicelluloses) and solvent soluble extractives in water (cold and hot) and ethanol:toluene (1:2 v.v.) mixture. The chemical composition of thermally modified Eucalyptus grandis juvenile wood was significantly changed by the VAP HolzSysteme® process compared to untreated wood. Only the wood thermally modified at final cycle temperature of 180 °C was significantly different for all the chemical analyses performed compared to untreated wood

NIR spectroscopy can evaluate the crystallinity and the tensile and burst strengths of nanocellulosic films

The near infrared (NIR) spectroscopy presents itself as an interesting non-destructive test tool as it enables a fast, simple and reliable way for characterizing large samplings of biological materials in a short period of time. This work aimed to establish multivariate models to estimate the crystallinity indices and tensile and burst strength of cellulosic and nanocellulosic films through NIR spectroscopy. NIR spectra were recorded from the films before tensile and bursting strength, and crystallinity tests. Spectral information were correlated with reference values obtained by laboratory procedures through partial least square regression (PLS-R). The PLS-R model for estimating the crystallinity index presented a coefficient of determination in cross-validation (R2cv) of 0,94 and the ratio of performance to deviation (RPD) was 3,77. The mechanical properties of the films presented a high correlation with the NIR spectra: R2p = 0,85 (RPD = 2,23) for tensile and R2p = 0,93 (RPD = 3,40) for burst strength. The statistics associated to the models presented have shown that the NIR spectroscopy has the potential to estimate the crystallinity index and resistance properties of cellulose and nanocellulose films on in-line monitoring systems