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Knowledge of the technological properties of wood is important for its use and the quality of its products. The aim was to assess the quality of charcoal produced from wood grown in the Cerrado biome. Wood samples of Handroanthus roseoalba (ipê branco), Handroanthus heptaphyllus (ipê roxo) and Piptocarpha rotundifolia ('blackheart') were selected. Charcoals from these samples were produced at two charring temperatures (500 and 550 °C). Basic density, total extractives, lignin and holocellulose, gravimetric yield, higher calorific value and immediate chemical properties of the charcoals were determined. Near infrared (NIR) spectra were obtained on the transverse and longitudinal faces of the wood using a DLP® NIRscan™ portable spectrometer. Partial least squares regression was used to adjust predictive models of charcoal properties using the NIR spectra measured in the precursor wood. The coefficients of determination in the cross-validation (R2cv) ranged from 0.49 to 0.87 for volatile materials, from 0.48 to 0.88 for fixed carbon and from 0.49 to 0.85 for higher calorific value of charcoal. The spectra generated better models for properties of charcoals produced at 500 °C. The models generated were satisfactory, indicating that the NIR spectrometry can predict the quality of charcoal before it is produced. [ABSTRACT FROM AUTHOR]

Considering the complexity and difficulty of identifying forest species, wooden disks were collected to verify the potential of colorimetry to distinguish native species from Araucaria Forest stands of the Lauraceae family. The following species were used: Nectandra megapotamica, Ocotea indecora, Ocotea diospyrifolia and Ocotea puberula. Nees, to provide data on these species that grow naturally in Santa Catarina state, southern Brazil, enriching a robust database that can be practically applied in the commercialization of native woods. Visible spectra and colorimetric parameters were obtained from each anatomical surface and the results were evaluated by comparing the mean of each species regarding radial trunk position and anatomical surface. The data were also submitted to principal component analysis and performance of discriminant models (k-NN, SVM and ANN) for species discrimination with raw and second-derivative data. In general, colorimetric data presented different behavior, and chromatic coordinates a* and b* had higher potential for distinguishing the species. According to the mean spectra, Ocotea indecora had reflectance values different from the other species. By principal component analysis, raw data indicated the separation only of Ocotea indecora, while second-derivative data allowed better distinction of species. In all discrimination models, second-derivative data produced the best results. Thus, the use of colorimetry has potential for wood distinction of the Lauraceae species evaluated, improving the oversight of illegally traded timber.

This study aimed to compare the mechanical performance of two truss typologies, the modified Fan and Howe trusses, using five different wood species: Cambará-rosa, Cupiúba, Angelim-pedra, Garapa, and Jatobá. The spans considered were 6, 9, 12, and 15 m, and the optimization algorithm used was a swarm intelligence algorithm to minimize the structure weight. The study found that wood is a sustainable and viable option for truss constructions, with different wood species having distinct mechanical properties that must be considered when designing the structure. The Howe truss typology presented lower results for the objective function in comparison with the modified Fan truss. The distribution of normal forces in the truss correlated with the characteristic strength in compression and tensile of the species. The Howe truss typology presented a larger amplitude in relation to the modified Fan truss typology in most of the conditions adopted for the Ultimate Limit State constraints. Constraints associated with deflection in the immediate condition were observed to limit the optimization process. The study used the matrix analysis method to evaluate internal efforts and nodal displacements in the trusses. In summary, this study demonstrates the importance of considering all constraints when dimensioning timber structures and the benefits of using different wood species for sustainable construction. [ABSTRACT FROM AUTHOR]

Enriching forests with native trees used for their high-value timber could allow productivity and biodiversity conservation goals to be achieved together. In certain Patagonian forests (e.g. low forests composed by resprouting species), this requires an analysis of the degree of canopy opening that guarantees planting success. We evaluated the influence of canopy opening intensity (OI) on the survival and height growth of a plantation of native tree species in three contrasting sites (south slope: SS, north slope: NS, and valley bottom: VB). At each site, we established an OI gradient of 0, 30, 50, and 70 % of initial biomass extraction, and planted Austrocedrus chilensis, Nothofagus dombeyi, N. pumilio, N. antarctica, N. alpina and N. obliqua (monitored for nine years). The optimal OI for average seedling survival was site-dependent; in SS the optimal survival was at intermediate OI (62 - 78 %), while in NS no differences were observed up to 50 % OI (32 %), and in VB plant survival was less than 3 %. N. obliqua and A. chilensis had the highest survival rate (60 % and 97 %, respectively). Annual plant growth varied among sites, with 27 ± 6 cm/year in SS, 10 ± 3 cm yr¹ in NS, and 5 ± 2 cm yr¹ in VB. N. obliqua reached the highest average plant height, with 4.2 ± 2 m in SS and 1.8 ± 1 m in NS. In SS most of the species grew from 18 to 60 % annually. Our results showed that management schemes should be species and site specific. We recommend planting on wetter slopes and initially removing up to 50 % woodland biomass. [ABSTRACT FROM AUTHOR]

The study investigates the effect of UV irradiation on different native and exotic wood species which is an open subject of research. Thirteen native wood species and ten exotic wood species, totally twenty-three wood species, all important for wood industry in Turkey, were subjected to UVA-340nm irradiation with a constant irradiance of 0.89 W/m2/nm and a temperature of 60 °C for 2, 4, 8, 16, 24, 48, 72, 96, 120, 144, 168, 252 and 336 h to determine the critical degradation time for the wood species. A short exposure time (from 2h to 48h) was especially studied since the previous studies reported that important and rapid changes occurred within the initial exposure periods. The effect of UV irradiation on wood surfaces was investigated by color, surface roughness, and FTIR-ATR measurements. The results proved that UV radiation caused a rapid color change for extractive-rich wood species at the initial period of exposure (16h–48h) which decreases upon prolonged exposure. The overall color change and surface roughness were higher for native wood species in a long exposure period than for exotic ones. Elm, oak, plane, walnut, acacia and linden as native wood species, iroko, tiama, acajou, okoume, garapa, sapelli, dibetou and teak as exotic wood species were found to be more resistant to color changes in prolonged irradiation periods, probably due to content of their components especially extractives and lignin. Similar to greater color change found within the beginning of the irradiation period (16h–48h), the first 8h–24h seemed to cause a greater increase in roughness for exotic species and 16h–24h for native wood species probably due to the changes in surface chemistry. Acacia, elm, cherry, beech, tiama, teak and okoume had the highest RI whilst S. pine, ash, poplar, plane, sapelli, limba and iroko had the lowest RI among the wood species. FTIR–ATR analysis demonstrated that UV light ended up with photodegradation of lignin and photooxidation of hemicelluloses which leads carbonyl-containing chromophores, even after short-time exposures (8h–24h). • Twenty-three wood species were exposed to UV irradiation from 2h to 336h. • The first 8–48 h of exposure period was found to be important for wood properties. • Color and roughness changes were higher for native wood species than for exotic ones. • Iroko, elm, tiama, acajou and okoume were found to be more resistant to color changes. • Significant changes occurred in lignin and hemicellulose component on irradiated surfaces. [ABSTRACT FROM AUTHOR]

This study aimed to compare the mechanical performance of two truss typologies, the modified Fan and Howe trusses, using five different wood species: Cambará-rosa, Cupiúba, Angelim-pedra, Garapa, and Jatobá. The spans considered were 6, 9, 12, and 15 m, and the optimization algorithm used was a swarm intelligence algorithm to minimize the structure weight. The study found that wood is a sustainable and viable option for truss constructions, with different wood species having distinct mechanical properties that must be considered when designing the structure. The Howe truss typology presented lower results for the objective function in comparison with the modified Fan truss. The distribution of normal forces in the truss correlated with the characteristic strength in compression and tensile of the species. The Howe truss typology presented a larger amplitude in relation to the modified Fan truss typology in most of the conditions adopted for the Ultimate Limit State constraints. Constraints associated with deflection in the immediate condition were observed to limit the optimization process. The study used the matrix analysis method to evaluate internal efforts and nodal displacements in the trusses. In summary, this study demonstrates the importance of considering all constraints when dimensioning timber structures and the benefits of using different wood species for sustainable construction.

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Herein, cellulose nanofibers (PO‐CNFs) and cellulose nanocrystals (PO‐CNCs) are prepared directly from native softwood spruce and hardwood beech via the same alkaline periodate oxidation under equal conditions. PO‐CNFs and PO‐CNCs are obtained by simply regulating the reaction time between 2 and 7 d. Of particular note, the preparation of CNFs is achieved using the alkaline periodate oxidation. PO‐CNFs obtained from spruce and beech have average diameters of 7.2 ± 3.1 and 6.8 ± 3.0 nm as well as average lengths of 487.1 ± 69.0 and 452.1 ± 80.0 nm, respectively. The PO‐CNCs obtained from spruce and beech are 4.6 ± 2.0 and 4.8 ± 2.5 nm in diameter as well as 181.6 ± 49.4 and 168.4 ± 59.0 nm in length, respectively. These nanocelluloses contain carboxy groups that enable good colloidal stability of nanocelluloses in water. The nanocellulose content isolated from spruce and beech increase with the reaction time and reach 1.35 ± 0.20 and 1.24 ± 0.10 mmol g–1 after oxidation for 7 d, respectively. Both PO‐CNFs and PO‐CNCs can be used for the formation of highly transparent films with good mechanical properties. [ABSTRACT FROM AUTHOR]

The differentiation between the charcoal produced from (Eucalyptus) plantations and native forests is essential to control, commercialization, and supervision of its production in Brazil. The main contribution of this study is to identify the charcoal origin using macroscopic images and Deep Learning Algorithm. We applied a Convolutional Neural Network (CNN) using VGG-16 architecture, with preprocessing based on contrast enhancement and data augmentation with rotation over the training set images. on the performance of the CNN with fine-tuning using 360 macroscopic charcoal images from the plantation and native forests. The results pointed out that our method provides new perspectives to identify the charcoal origin, achieving results upper 95 % of mean accuracy to classify charcoal from native forests for all compared preprocessing strategies.

A crescente procura da matéria-prima vem ocasionando o encarecimento do produto, desse modo, as empresas devem possuir um processo de desdobramento que obtenha melhor aproveitamento, levando ao aumento do rendimento na produção. O objetivo deste trabalho foi avaliar o coeficiente de rendimento volumétrico de três espécies florestais amazônicas: Hymenolobium petraeum, Goupia glabra e Manilkara spp. Foram selecionadas cinco toras de madeira aleatoriamente para cada espécie analisada, o volume da madeira em tora foi obtido pelos métodos de Smalian e Francon. Posteriormente, foi obtido o volume da madeira processada, medindo-se as dimensões de cada peça serrada correspondente a cada uma das toras. O cálculo de rendimento foi determinado pela razão entre o volume de madeira serrada e o volume da madeira em tora. A análise estatística foi realizada através do teste de Tukey com o intuito de avaliar as médias levando em consideração um delineamento inteiramente casualizado, utilizando o programa ASSISTAT Versão 7.7. O rendimento médio das três espécies estudadas foi equivalente a 50,83%, valor satisfatório para as condições da região, a qual não apresenta nível de automação elevado e nem mão de obra qualificada. The growing demand for raw materials is causing the increasing of the product, thus, companies must have a process of unfolding that obtains better exploitation, succeeding the increase in yield in production. The aim of this work was to evaluate the coefficient of volumetric yield of Amazon forests species: Hymenolobium petraeum, Goupia glabra and Manilkara spp. Five wood logs were randomly selected for each species analyzed, the observed volume of wood was based on the geometric cubing methods (Smalian and Francon). Subsequently the measurement of the volume of processed wood was carried out by the romaneio procedure, the calculation of the yield of the volume of each log was determined before the unfolding process. The statistical analysis was conducted through Tukey test aimed to evaluate the averages taking into consideration an entirely randomized design, using the program version 7.7. The average yield of the three studied species has been equivalent to 50.83% satisfactory value for the conditions of the region, which does not present high levels of automation and not skilled labor.

The objective of this study was to determine and evaluate the yield of four (4) diameter classes in function of quality of logs, in logwood processing of Cedrinho (Erisma uncinatumWarm.). 20 logs of four diameter classes between 46 and 85 cm were selected and classified in terms of quality, being 5 logs for each diameter class. Diameter class I resulted in the lowest yield and diameter class III showed the highest yield. Yield increased according to the diameter of the logs in classes I, II and III. Class IV logs with larger diameters had quality defects such as cracks and internal flaws, causing a small yield drop. It could be concluded that there was a correlation between diameter and yield. [ABSTRACT FROM AUTHOR]

Consumer practices of native wood in the residential segment of the greatest urban center which uses wood in the Aysén region, as is the case of the city of Coyhaique, are characterized here. By polling 164 homes -according to a multiphasal sampling- the volumes of wood extracted in stereo cubic meters were quantified, classifying the type of wood and identifying the exploited arboreal species. We establish that the broad hegemony of the type of wood denominated as "Green", obtained from standing trees, more so than "dead" wood, comes from burned trunks from old forest fires of anthropic origin. In both types of wood, Lenga (Nothofagus pumilio), supports the greatest pressure of use, accumulating 78.6% of the total absolute volume, which corresponds to 2006 stereo cubic meters. The applied polling also permitted the configuration of a special distribution of sectors of the forest which provide the wood for the inhabitants of the regional capital. This special pattern compromises the forested communities situated in the basin of the Aysén river, particulariy through the fluvial planes of the Simpson and Maniguales sub-basins. Together with notoriously surpassing the annual production of lumber in the region, the volumes of wood that support the urban demand represent the greatest negative impact on the structure and dynamics of patagonian forest ecosystems. [ABSTRACT FROM AUTHOR]