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The commercial value of teak wood is associated with its heartwood, which has a naturally darker color than sapwood. To reduce this color disparity, thermal modification can be used to homogenize the color between sapwood and heartwood by minimizing color differences. This research aimed to assess the effectiveness of thermal modification in making the color of teak sapwood similar to that of heartwood. Thermal modification was carried out at 160, 180, 200, and 220 °C for 150 min. Thermal modification of teak sapwood at 180 °C ensured greater color similarity to the heartwood of a fast-growing 16-year-old plantation. The material darkened with increasing process temperature. There was a change in the content of soluble substances, and hot water extraction had greater correlations with hue angle, lightness, and yellowness. Thermal modification also reduced the number of hydroxyl groups and improved the wood's thermal stability. [ABSTRACT FROM AUTHOR]

The clonal materials of Tectona grandis L. f. in fast-growing plantations exhibit faster growth than the seminal materials. Therefore, it is necessary to investigate the differences in wood drying to ensure the quality and yield of the final product. This study evaluated the outdoor drying behavior of three genotypes of teak lumber. Two clonal genotypes (G1 and G2) and one of seminal origin (G3) were assessed. Boards measuring 30 × 150 × 1000 mm (thickness × width × length) were produced from the basal logs. The average moisture content (79.3, 64.9, and 60,1%), final moisture content (10.8, 9.8, and 11.6%), and mean drying rate (1.2, 0.97, and 0.85%.day-1) were observed in the wood from genotypes G1, G2 and G3, respectively. The clonal material crooked and bowed below 5 mm.m-1, which is considered the tolerance limit for both warpings. The seminal material had a greater incidence of splitting. The clonal genotypes G1 and G2 had similar qualities and presented higher drying rates, final moisture contents below 11% and a lower incidence of defects, especially splitting, compared to the naturally seeded material. [ABSTRACT FROM AUTHOR]

Teakwood from fast-growth plantations is commercialized at increasingly younger ages for economic reasons. However, wood features are influenced by the age of the tree. This study examined how age affects heartwood proportion, color parameters, chemical composition, and natural teakwood durability. Trees with 5, 10, 15, and 20 years of fastgrowth at commercial plantations located in Mato Grosso, Brazil were evaluated. The base diameter of the trees ranged from 13.1 (5 years) to 28.3 cm (20 years), and the heartwood percentage increased from 16.3 to 60.0%, respectively. The color parameters in the CIELab system indicated that wood became darker and more saturated, and the predominance of yellow color decreased compared with red as age advanced. The total extractive content ranged between 7.4 (5 years) and 9.6% (15 years), without a clear trend of age affecting the extractive content. The extractives from five-year-old wood were mainly composed of tectoquinone (43.3%), phthalic acid (19.1%), and 1,3-indandione (9.2%), while those from 20-year-old wood were mainly composed of tectoquinone (60.7%), lapachol (13.8%), and phthalic acid (9.7%). Teakwood can be classified as resistant (5 years) to very resistant (20 years) after being submitted to an accelerated decay test. [ABSTRACT FROM AUTHOR]

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Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Wood Science / Revista Ciência da Madeira is the property of Brazilian Journal of Wood Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira is the property of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The pellets are becoming an important renewable source of energy for industrial and domestic use. The consumer market is increasingly demanding in terms of product quality and this may be improved through the use of various additives, such as kraft lignin. The objective of this study was to evaluate the quality of eucalyptus pellets produced with the addition of different percentages of kraft lignin. The raw material used for production of pellets was wood with bark of an Eucalyptus grandis x E. urophylla clone, with approximately five years of age, obtained from commercial planting, and 10% of waste of eucalyptus harvest (tops, leaves and branches). Excluding the control (0% lignin) was added 1, 2, 3, and 5% kraft lignin, relative to the dry mass of raw material. The pellets were produced in a laboratory pelletizer with a horizontal circular array. The following properties of the pellets were evaluated: moisture content, gross and net calorific value, unit density, bulk density, energy density, ash content, length and diameter, hardness, mechanical durability and fines content. The addition of kraft lignin contributed to improving the pellets physical and mechanical properties, as regards the density, mechanical durability, fines and hardness. The addition of lignin caused the elevation of the levels of ash and moisture content of the pellets. It is concluded that addition of lignin to pellet production is feasible, since lignin is used with lower contents of ash and moisture. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira is the property of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the lack of information about wood properties and charcoal quality from native species, this work was carried out aiming at to characterize the wood anatomical structure of Piptadenia gonoacantha and determine the yield and properties of charcoal. The wood anatomy was described, and it was determined the fibers and vessels dimensions, basic density and higher heating value (HHV). Bulk density, chemical analysis, and HHV were determined for charcoal. The average vessel diameter was 121.30 μm, with 15 vessels mm-2. The fiber dimensions were: length, 0.82 mm, width, 17.54 μm, lumen diameter, 8.02 μm, wall thickness, 4.76 μm, and wall fraction of 54.28%. The basic wood density was 590 kg m-3 and HHV was 4650 kcal kg-1. The charcoal yield was 37.10%. The content of volatile matter, ash and fixed carbon were 23.26%, 2.39% and 74.35%, respectively. Charcoal HHV was 7.719.27 kcal kg-1 and bulk density was 460 kgm-3. Wood showed satisfactory quality for charcoal production, and this meets the requirements of the steel industry. [ABSTRACT FROM AUTHOR]