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Vol 17, No 1 (2015) by Silvana Nisgoski
Papers by Silvana Nisgoski
Forest Science, Jun 8, 2021
Anais Da Academia Brasileira De Ciencias, May 13, 2016
Ciencia Florestal, Mar 29, 2015
Anais Da Academia Brasileira De Ciencias, 2022
Journal of Tropical Forest Science, Jul 31, 2017
Australian Journal of Botany, 2018
Ciência e Natura, Dec 14, 1998
DOAJ (DOAJ: Directory of Open Access Journals), 2005
The main objective of this research was to compare anatomical wood characteristics of the popular... more The main objective of this research was to compare anatomical wood characteristics of the popular varieties of Mimosa scabrella Bentham known as bracatinga-branca, bracatinga-vermelha and bracatingaargentina. The material used in this work was collected from 6 to 7 years old trees of the popular varieties from areas located in Colombo municipality, State of Paraná, owned by Embrapa Florestas. Botanic for anatomical characterization of wood material was identified and described. Results did not show differences of anatomical characteristics between the bracatinga-branca and bracatinga-vermelha. The bracatingabranca and bracatinga-vermelha showed statistically differences in relation to bracatinga-argentina to average values in pores tangential diameter, pores quantity per square mm, vessel elements individual length, axial parenchyma cells diameter, unisseriate and multisseriate rays width. In conclusion, the observations contribute to a better understanding of the differences showed by the popular varieties.
Ciência Florestal
Lignin, the second most abundant biopolymer on the planet, has properties that can be widely expl... more Lignin, the second most abundant biopolymer on the planet, has properties that can be widely explored, moving from waste to products with high added value. Therefore, this work aimed to extract and characterize Klason and Kraft lignins from sawdust and black liquor, considered industrial waste. The raw material used was Eucalyptus grandis chips. To obtain Klason lignin according to TAPPI 222 om-02 (2002), part of the chips were transformed into sawdust. To obtain Kraft lignin, another part of the chips passed through a digester to obtain black liquor, which was subsequently subjected to acid precipitation. The characterization of lignins was performed by granulometry analysis, scanning electron microscopy with elemental chemical analysis (EDS), transmission electron microscopy, medium infrared spectroscopy, thermogravimetric analysis and differential calorimetry. Microscopy analyzes showed irregular structures of various shapes, including spherical structures, most evident and frequ...
e-Acadêmica, Dec 24, 2022
Maderas. Ciencia y tecnología
Forest Systems
Aim of study: The aim of this study was to verify the differences in VIS/NIR spectra and leaf col... more Aim of study: The aim of this study was to verify the differences in VIS/NIR spectra and leaf color parameters of leaves of Eucalyptus badjensis, E. benthamii, E. dunnii, E. grandis, E. globulus and E. saligna, at four ages, and their influence on species discrimination. Area of study: São Mateus do Sul, Paraná, Brazil. Material and methods: Seedlings of the six species, with four replicates for each, were acclimatized in the same environment, in October 2015, in an entirely randomized design. Leaf samples were collected from plants that were 6, 8, 10 and 12 months old. Three leaves from each of four plants at each age were analyzed. Five parameters were recorded referring to the adaxial surface of each leaf, with a total of 15 records from repetitions and 60 per species at each age. The evaluation was performed in the spectral ranges from 360-740 nm (VIS) and 1000-2500 nm (NIR). Principal component analysis and linear discriminant analysis were performed. Main results: Th...
In: CONGRESSO BRASILEIRO DE POLÍMEROS, 13., 2015, Natal. Anais. [São Carlos: Associação Brasileira de Polímeros], 2015., 2015
Species discrimination by charcoal analysis is possible, because the wood anatomical structure re... more Species discrimination by charcoal analysis is possible, because the wood anatomical structure remains almost intact after carbonization process. Studies in this area are rare and directed to paleoecology and paleoetnobotany. Thus, this study aimed to characterize anatomically the carbonized wood of Copaifera cf. langsdorfii Desf. and Dipteryx odorata (Aubl.) Wild., proceeding from north region of Mato Grosso state, in order to provide information to manage its illegal commerce. From each species were carbonized ten samples with dimensions of 2 x 2 x 5 cm in muffle furnace, in stage program and highest temperature of 450°C for 30 minutes, for seven hours. Final temperature applied does not change anatomical structure from both species, allowing its differentiation. The crystals formatremained without alterations, being visible little split.
SN Applied Sciences, 2020
Forest Science, Jun 8, 2021
Anais Da Academia Brasileira De Ciencias, May 13, 2016
Ciencia Florestal, Mar 29, 2015
Anais Da Academia Brasileira De Ciencias, 2022
Journal of Tropical Forest Science, Jul 31, 2017
Australian Journal of Botany, 2018
Ciência e Natura, Dec 14, 1998
DOAJ (DOAJ: Directory of Open Access Journals), 2005
The main objective of this research was to compare anatomical wood characteristics of the popular... more The main objective of this research was to compare anatomical wood characteristics of the popular varieties of Mimosa scabrella Bentham known as bracatinga-branca, bracatinga-vermelha and bracatingaargentina. The material used in this work was collected from 6 to 7 years old trees of the popular varieties from areas located in Colombo municipality, State of Paraná, owned by Embrapa Florestas. Botanic for anatomical characterization of wood material was identified and described. Results did not show differences of anatomical characteristics between the bracatinga-branca and bracatinga-vermelha. The bracatingabranca and bracatinga-vermelha showed statistically differences in relation to bracatinga-argentina to average values in pores tangential diameter, pores quantity per square mm, vessel elements individual length, axial parenchyma cells diameter, unisseriate and multisseriate rays width. In conclusion, the observations contribute to a better understanding of the differences showed by the popular varieties.
Ciência Florestal
Lignin, the second most abundant biopolymer on the planet, has properties that can be widely expl... more Lignin, the second most abundant biopolymer on the planet, has properties that can be widely explored, moving from waste to products with high added value. Therefore, this work aimed to extract and characterize Klason and Kraft lignins from sawdust and black liquor, considered industrial waste. The raw material used was Eucalyptus grandis chips. To obtain Klason lignin according to TAPPI 222 om-02 (2002), part of the chips were transformed into sawdust. To obtain Kraft lignin, another part of the chips passed through a digester to obtain black liquor, which was subsequently subjected to acid precipitation. The characterization of lignins was performed by granulometry analysis, scanning electron microscopy with elemental chemical analysis (EDS), transmission electron microscopy, medium infrared spectroscopy, thermogravimetric analysis and differential calorimetry. Microscopy analyzes showed irregular structures of various shapes, including spherical structures, most evident and frequ...
e-Acadêmica, Dec 24, 2022
Maderas. Ciencia y tecnología
Forest Systems
Aim of study: The aim of this study was to verify the differences in VIS/NIR spectra and leaf col... more Aim of study: The aim of this study was to verify the differences in VIS/NIR spectra and leaf color parameters of leaves of Eucalyptus badjensis, E. benthamii, E. dunnii, E. grandis, E. globulus and E. saligna, at four ages, and their influence on species discrimination. Area of study: São Mateus do Sul, Paraná, Brazil. Material and methods: Seedlings of the six species, with four replicates for each, were acclimatized in the same environment, in October 2015, in an entirely randomized design. Leaf samples were collected from plants that were 6, 8, 10 and 12 months old. Three leaves from each of four plants at each age were analyzed. Five parameters were recorded referring to the adaxial surface of each leaf, with a total of 15 records from repetitions and 60 per species at each age. The evaluation was performed in the spectral ranges from 360-740 nm (VIS) and 1000-2500 nm (NIR). Principal component analysis and linear discriminant analysis were performed. Main results: Th...
In: CONGRESSO BRASILEIRO DE POLÍMEROS, 13., 2015, Natal. Anais. [São Carlos: Associação Brasileira de Polímeros], 2015., 2015
Species discrimination by charcoal analysis is possible, because the wood anatomical structure re... more Species discrimination by charcoal analysis is possible, because the wood anatomical structure remains almost intact after carbonization process. Studies in this area are rare and directed to paleoecology and paleoetnobotany. Thus, this study aimed to characterize anatomically the carbonized wood of Copaifera cf. langsdorfii Desf. and Dipteryx odorata (Aubl.) Wild., proceeding from north region of Mato Grosso state, in order to provide information to manage its illegal commerce. From each species were carbonized ten samples with dimensions of 2 x 2 x 5 cm in muffle furnace, in stage program and highest temperature of 450°C for 30 minutes, for seven hours. Final temperature applied does not change anatomical structure from both species, allowing its differentiation. The crystals formatremained without alterations, being visible little split.
SN Applied Sciences, 2020
International Wood Products Journal, 2019
ABSTRACT The aim of this study was to provide information on the anatomical characteristics of ca... more ABSTRACT The aim of this study was to provide information on the anatomical characteristics of carbonized wood of Prosopis alba and also test the potential of near-infrared in discrimination of wood and charcoal from natural or planted forest. The samples from four different sites were carbonized at 450°C in muffle furnace, both wood and charcoal anatomical qualitative and quantitative features were analysed and measured, and infrared analyses were performed. The qualitative characteristics of the wood anatomy remained in charcoal and the vessel diameter was the only quantitative feature with a statistically significant difference between them, hence the anatomical aspects were insufficient to distinguish between sites. Near-infrared spectroscopy with multivariate statistics showed good results in segregating the samples from planted forest from those of natural forests by using partial least square regression both in wood and carbonized material, indicating a good potential use in distinguishing material from different origins.
This article reports the first study of the influence of the Brazilian process of thermal modific... more 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.
This study investigated the effect of plasma treatment on changes of surface wettability of wood ... more This study investigated the effect of plasma treatment on changes of surface wettability of wood flooring from two Brazilian tropical species, Hymenaea spp. (rode locus) and Tabebuia spp. (lapacho). Wood flooring samples were plasma treated at low pressure in a helium atmosphere. Energy level was set at 100 W and four glow discharge times (5, 15, 30 and 45 s) were tested. Changes in wettability were investigated by measuring apparent contact angle, droplet volume and spreading contact area. The results showed less susceptibility of lapacho wood to the plasma treatments, while reduction of apparent contact angle in rode locus wood reached up to 76% for longer discharge times. In general, discharge time of 15 s produced the same effect as discharge of 45 s on wettability, which is important for industrial applications. Visual analyses revealed increase of water droplet spreading on lapacho wood surface, even though the variation of spreading contact area was not significant. Plasma treatment is feasible to improve wettability of tropical woods. Nevertheless, these findings should be investigated further due to the intrinsic characteristics of woods from tropical species.
Because of the need for identification of forest species, especially for detection of illegal woo... more Because of the need for identification of forest species, especially for detection of illegal wood trade, the objective of this study was to evaluate the potential of colorimetry for differentiation of Inga vera Muellera campestris and Machaerium paraguariense species of the Fabaceae family, native to the Araucaria Forest in the state of Santa Catarina, southern Brazil. Discs at breast height were collected from three trees of each species and the colorimetric parameters (L*, a*, b*, C* and h) and visible spectra were evaluated in different radial position of the trunk (near bark, intermediate and near pith) and three different anatomical sections (transversal, radial and tangential surfaces). Mean values of hue angle (h) among the colorimetric parameters resulted in the highest potential for species discrimination. With respect to radial trunk position and anatomical section, parameters a* (green-red) and h were not statistically different, independent of the wood samples evaluated. For other parameters (L*, b* and C*), each species presented distinct results. Principal component analysis with second derivative of visible spectra discriminated all species. Colorimetry associated with chemometrics allowed to distinguish I. vera, M. campestris and M. paraguariense.
RESUMEN El objetivo del presente estudio fue determinar las propiedades físicas de la madera de G... more RESUMEN El objetivo del presente estudio fue determinar las propiedades físicas de la madera de Guazuma crinita por el método convencional, así como estimar estas propiedades por espectroscopia infrarroja cercana (NIR) a través del desarrollo de modelos de calibración multivariada. Las muestras fueron obtenidas de tres niveles del eje longitudinal en 5 árboles para 5 y 8 años de edad seleccionados al azar de una plantación en la zona de Puerto Inca, departamento de Huánuco (Perú). Se determinó la densidad básica, contracción total volumétrica, tangencial y radial por el método destructivo o convencional. Los modelos fueron desarrollados por regresión de mínimos cuadrados parciales (PLS) mediante transformaciones matemáticas. Para la validación de los mo-delos se empleó un grupo de muestras que no participo en el desarrollo del modelo. Se encontró diferencias estadísticas significativas (F 5años = 191,5; F 8años =84,9) entre las tres alturas en el fuste. Para densidad básica y contracción volumétrica se encontró valores de 2 c R (0,88 y 0,83) y RPD p (1,55 y 3,27) aceptables para la predicción. Palabras claves: Contracción radial, contracción tangencial, contracción volumétrica, densidad básica, regresión de mínimos cuadrados parciales. ABSTRACT The aim of the present study was to determine the physical properties of the Guazuma crinita wood by conventional methods, as well as to estimate these properties by near infrared spectroscopy (NIR) through the development of multivariate calibration models. The samples were obtained from five trees and from three levels longitudinally for 5 and 8 years of age randomly selected from a plantation in Puerto Inca, Department of Huánuco (Perú). Basic density, volumetric, tangential and radial contraction were determined by the conventional methods. Models were developed by regression of partial least squares (PLS) through mathematical transformations. For the validation of the models, a new group of samples-which did not participate in the development of the model were used. Statistical significance was found F 5años = 191,5; F 8 años =84,9) between the different heights in the stem. Basic density and volumetric contraction show values of 2 c R (0,88 and 0,83) and RPD p (1,55 and 3,27) acceptable for prediction.
RESUMEN El objetivo del presente estudio fue determinar las propiedades físicas de la madera de G... more RESUMEN El objetivo del presente estudio fue determinar las propiedades físicas de la madera de Guazuma crinita por el método convencional, así como estimar estas propiedades por espectroscopia infrarroja cercana (NIR) a través del desarrollo de modelos de calibración multivariada. Las muestras fueron obtenidas de tres niveles del eje longitudinal en 5 árboles para 5 y 8 años de edad seleccionados al azar de una plantación en la zona de Puerto Inca, departamento de Huánuco (Perú). Se determinó la densidad básica, contracción total volumétrica, tangencial y radial por el método destructivo o convencional. Los modelos fueron desarrollados por regresión de mínimos cuadrados parciales (PLS) mediante transformaciones matemáticas. Para la validación de los mo-delos se empleó un grupo de muestras que no participo en el desarrollo del modelo. Se encontró diferencias estadísticas significativas (F 5años = 191,5; F 8años =84,9) entre las tres alturas en el fuste. Para densidad básica y contracción volumétrica se encontró valores de 2 c R (0,88 y 0,83) y RPD p (1,55 y 3,27) aceptables para la predicción. Palabras claves: Contracción radial, contracción tangencial, contracción volumétrica, densidad básica, regresión de mínimos cuadrados parciales. ABSTRACT The aim of the present study was to determine the physical properties of the Guazuma crinita wood by conventional methods, as well as to estimate these properties by near infrared spectroscopy (NIR) through the development of multivariate calibration models. The samples were obtained from five trees and from three levels longitudinally for 5 and 8 years of age randomly selected from a plantation in Puerto Inca, Department of Huánuco (Perú). Basic density, volumetric, tangential and radial contraction were determined by the conventional methods. Models were developed by regression of partial least squares (PLS) through mathematical transformations. For the validation of the models, a new group of samples-which did not participate in the development of the model were used. Statistical significance was found F 5años = 191,5; F 8 años =84,9) between the different heights in the stem. Basic density and volumetric contraction show values of 2 c R (0,88 and 0,83) and RPD p (1,55 and 3,27) acceptable for prediction.
The search for new technologies to improve adhesives and the properties of reconstituted wood pan... more The search for new technologies to improve adhesives and the properties of reconstituted wood panels is constant, and nanotechnology is a tool for this purpose. The aim of this study is investigating the effect of adding nanocellulose in the formulation of the adhesive phenol-formaldehyde on the physico-mechanical properties of Pinus taeda plywood panels. Three ratios of nanofibrillated cellulose (NFC) were added to the adhesive formulation used to produce plywood panels: 0,026 %; 0,038 % or 0,064 %. The panels were tested according to the European standards; apparent density, resistance to parallel and perpendicular flexure and glue line shear strength were determined after 6 hours of boiling and after the boiling cycle for the 1 st glue line (face) and 2 nd glue line (core). The use of NFC in the adhesive caused an increase of viscosity and reduction of the gel time of the adhesive. The apparent density of the panels was not influenced by the addition of NFC, but the properties of parallel bending, perpendicular flexing and glue line shear were sensitive to the addition of NFC. The NR2 treatment (0,038 % NFC) presented the best results in the mechanical tests.
Thermal modification is a treatment that seeks to improve the properties of wood and reduce the h... more Thermal modification is a treatment that seeks to improve the properties of wood and reduce the heterogeneity in its color. The objective of this work was to evaluate the effect of thermal treatment on the anatomical, chemical, physical, mechanical, colorimetric, and thermal stability properties of teakwood. For this, teakwood samples were treated by an industrial autoclave at final cycle temperature of 160 ºC. The reduction of cell wall thickness, the formation of cross-fissures and the crystallization of the wax inside the pores were observed in the anatomical structure. Chemically, the extractives evaporated and the polysaccharides ruptured, of which hemicellulose was the most affected. The heat treatment promoted lower equilibrium moisture, reducing the hygroscopicity and improving the dimensional stability of the wood. Considering the mechanical properties, the rupture modulus and the longitudinal and tangential hardness decreased after the heat treatment. The color of the wood changed significantly, from pink to dark brown. The treated wood had higher thermal stability, with greater weight loss at higher temperatures than the untreated wood.