Silvana Nisgoski

A database for automatic classification of forest species

Forest species can be taxonomically divided into groups, genera, and families. This is very important for an automatic forest species classification system, in order to avoid possible confusion between species belonging to two different groups, genera, or families. A common problem that researchers in this field very often face is the lack of a representative database to perform their experiments. To the best of our knowledge, the experiments reported in the literature consider only small datasets containing few species. To overcome this difficulty, we introduce a new database of forest species in this work, which is composed of 2,240 microscopic images from 112 different species belonging to 2 groups (Hardwoods and Softwoods), 85 genera, and 30 families. To gain better insight into this dataset, we test three different feature sets, along with three different classifiers. Two experiments were performed. In the first, the classifiers were trained to discriminate between Hardwoods and Softwoods, and in the second, they were trained to discriminate among the 112 species. A comprehensive set of experiments shows that the tuple Support Vector Machine (SVM) and Local Binary Pattern (LBP) achieved the best performance in both cases, with a recognition rate of 98.6 and 86.0% for the first and second experiments, respectively. We believe that researchers will find this database a useful tool in their work on forest species recognition. It will also make future benchmarking and evaluation possible. This database will be available for research purposes upon request to the VRI-UFPR.

Vacuum Drying Kinetics of Yacon (Smallanthus sonchifolius) and the Effect of Process Conditions on Fractal Dimension and Rehydration Capacity

This work aimed at studying the drying kinetics of yacon slices during vacuum drying and evaluating the effect of drying temperature, slice thickness, and citric acid concentration in the enzymatic inhibition solution on the fractal dimension and rehydration ratio of yacon slices. The drying kinetics was tentatively fitted to various thin-layer drying models, and the best fit was obtained using the modified Page model. The fit was validated after evaluating the values of coefficient of determination and parameters percentage error. The final products fractal dimension, as calculated by the box counting method, was be between 1.5904 and 1.8358, which confirms that vacuum-dried yacon slices are fractals. Among the studied factors, drying temperature was found to negatively affect the fractal dimension and slice thickness was found to negatively affect the rehydration ratio. A good correlation was established between fractal dimension and moisture content, rehydration ratio, and hue angle, suggesting that the moisture, rehydration, and color measurements during yacon vacuum drying could be substituted or complemented by an image analysis.

Anatomical and energy characteristics of charcoal made from five species

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.

Characterization of Pinus spp needles and evaluation of their potential use for energy.

The demand for new energy sources is growing and awakening interest in the use of forest residues. Charcoal was prepared at carbonization temperatures of 500 oC, 600 °C and 700 °C in order to evaluate the potential use of Pinus sp needles for energy. The anatomical and chemical characteristics of the needles and the charcoal produced were also evaluated. The needles were found to have ash content of 2.32% and gross calorific value of 20.30 MJ/kg. The calorific value increased by 45%, reaching 29.64 MJ/kg, after carbonization carried out at 600 oC. This value is higher than that for charcoal made from eucalyptus (19.25 MJ/kg) and even coconut husks (23.55 MJ/kg), showing the high energy potential of these needles.

Caracterização Física e Térmica de Compósito de Poliuretano Derivado de Óleo de Mamona Associado com Partículas de Bambu

Composites of Polyurethane (PU) resin derived from castor oil and bamboo particles (Dendrocalamus giganteus) were prepared by pressing with 10, 15 and 20% weight of PU. The aim of this study was to develop a new application of wastes from bamboo manufacture, minimizing the negative impact to the environment, adding a resin free of volatile organic compounds (COV). The composite characterization was performed with physical and thermogravimetric analysis. The association of PU and bamboo particles produced the expected effects, including a decrease in moisture content, swelling and water absorption as PU percentage increased. The Shore D hardness increased with the percentage of resin PU in the composite.

Morfologia e densidade básica das folhas de tucum ( Bactris inundata Martius) como fonte de fibras celulósicas para papel.

This work aims at making an evaluation of the morphological characteristics and density of fibers obtained from straws of Bactris inundata palms leaves. A value of 0,342 g/cm³ was found for the basic density. Bactris inundata presented two different fibers due to their morphological characteristics: Fiber A, with average fiber length of 0,69 mm, width of 10,56 μm, lumen width of 2,63 μm and cell-wall thickness of 3,97 μm, classified as short; Fiber B, with length of 2,33 mm, width of 7,66 μm, lumen width of 1,85 μm and cell-wall thickness of 2,91 μm, classified as long. The fiber “A” of Bactris inundata presented a low coefficient of flexibility of 25,12%, and a rather high felting index of 66,85. The fiber “B” of Bactris inundata presented a low coefficient of flexibility (24,09%), and a high felting index (313,59). The relationship between fibers dimensions indicated that they could be used in kraft production with good indexes of physical-mechanical resistance in some properties.

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.

Anatomia do carvão de espécies florestais

O carvao vegetal mantem a estrutura anatomica da madeira que o originou e pode permitir sua identificacao botânica, a qual depende das caracteristicas da especie, o tamanho dos fragmentos do carvao e o estado de preservacao. A caracterizacao anatomica do carvao de dez especies florestais foi efetuada com o objetivo de auxiliar na identificacao e controle de carvao ilegal. A diferenciacao entre angiospermas e gimnospermas e bem evidente no lenho carbonizado. O diâmetro dos poros foi estatisticamente diferente entre a madeira e carvao na Vatairea guianensis, Mezilaurus itauba, Calophyllum brasiliense e Qualea cf. acuminata, e a frequencia dos poros na Vatairea guianensis, Manilkara huberi, Qualea cf. acuminata e Simarouba amara. A estrutura anatomica da madeira, de maneira geral, se mantem durante o processo de carbonizacao utilizando-se temperatura de 450oC, podendo-se identificar o material com base nas celulas componentes.

Microstructural aspects of thermally modified Eucalyptus grandis wood

Thermal modification of wood is a process that has drawn considerable attention of Brazilian researchers, but studies about the effect of this process on wood anatomy are scarce, even in the worldwide literature. The aim of this work was to perform a preliminary analysis of the effect of the Brazilian thermal modification process called VAP HolzSysteme® on the cell dimensions of Eucalyptus grandis wood. The investigated treatments corresponded to three final cycle temperatures (140, 160 and 180 °C), which were compared to untreated wood. Wood anatomy was analyzed qualitatively and quantitatively by scanning electron microscopy (SEM) and optical microscopy, in the latter case to measure the dimensions of fibers, vessel elements and ray parenchyma. The qualitative analysis using SEM indicated that no significant changes occurred on the structure of ray parenchyma, vessels and fibers tissues. Even tyloses was preserved in the vessel elements of thermally modified wood at the highest temperature (180 °C). Likewise, no quantitative changes were observed in the dimensions of fibers, vessels diameter and ray parenchyma height.

Preparation and Characterization of Nano Silica from Equisetum arvenses

With the progress of nanotechnology and increase in demand, several silica processing industries have started producing silica nanoparticles. As a result, the search for new sources capable of producing this material has been attracting the interest of many researchers. With this background, a study was carried out to obtain silica nano particles from the Equisetum arvenses, a plant that possesses one of the highest amounts of silicon. This paper presents the preparation of nano silica particles with different combinations of acid washing and calcination at varying temperatures between 773 K and 873 K. The nanoparticles produced were characterized for nitrogen adsorption, morphology using transmission electron microscope and structural analysis by X-ray fluorescence and diffraction. It was found that nanoparticles produced by two cycles of acid washing and calcination at 773 K gave the best results, producing a material with white color, the highest specific surface area of about 330 m²/g with diameter of about 8 nm, and 93.5% of amorphous silica. The nanoparticles obtained can be potential industrial raw material for many applications.