Abstract: The aim of this study was to determine how varying the inputted surface area value of wood samples would affect the determination of kiln-drying schedules using the drastic drying test. For this purpose, eight individuals of two Eucalyptus clones were selected. Specimens were obtained for drastic drying tests at 100 °C, to measure the basic density and to determine the initial moisture content. The initial and final temperatures and the drying potential were calculated in 100 mm × 50 mm × 10 mm samples, considering the surface area to be 130 cm² (Updated Method), in contrast to the surface area of 100 cm² that is commonly used in the method known as the Standard Method. Based on these findings, kiln-drying schedules were set for the lumber from each clone. Although the significant differences aforementioned, it was observed that the drying schedules developed by Standard Method and Updated Method are similar.

Abstract: The quantitative evaluation of longitudinal drying strain can provide relevant information for the processing wood and lumber industry, especially with regard to reaction wood in Corymbia, since little has been published. The objective of this work was to evaluate the effect of the steam conditioning and the cooling on the longitudinal drying strain (LDS) obtained from a strain gauge, called extensometer, in boards of both normal and tension wood of Corymbia citriodora. Lumbers 30 mm thick were produced and kiln dried at the initial temperature of 40°C, final temperature of 65°C and drying potential of 2,1. The LDS were measured before and after steam conditioning on hot and cold lumbers. It was observed that the conditioning did not reduce the LDS. Hot lumbers showed higher LDS values than the cold lumbers. The LDS values measured in normal, tension and opposite woods were statistically similar, indicating that the type of wood was not an influential factor in the appearance of longitudinal drying stresses. Extensometer proved to be feasible for measuring LDS, allowing its easy and quick quantification.

Abstract: In this work, the relationship between vessels parameters and the wood cleavage strength were studied to clarify the process of formation of this type of check, very common in Eucalyptus wood. The objective was to identify the relationship between the wood cleavage strength, the average area of the vessel, and the percentage area of vessels on the wood transverse surface. For this, two Eucalyptus grandis trees at 22 years old were felled and specimens for the cleavage test were produced to determine the wood cleavage strength. From these specimens, samples were taken to determine the average area of the vessel and the percentage area of vessels, aiming at adjusting mathematical models that explain the variation in the cleavage strength. The results showed that the higher the average area of the vessel and the percentage of area occupied by vessels in the wood, the lower its cleavage strength. The multiple linear regression model can estimate the cleavage strength as a function of the average area of the vessel, and the percentage area of the vessels.

ABSTRACT Activated carbons (AC) are high porosity and adsorptive carbonaceous materials. These adsorbents can be produced using different organic materials. Precursor material properties may impact their quality. This study aimed to produce activated carbon from Tectona grandis wood wastes, besides determining efficiency in adsorption of different pollutants. Chemical activation, with ZnCl2 (AC_ZnCl2) and CuSO4 (AC_CuSO4), and physical activation, with CO2 (AC_CO2) were performed. Activated carbons were characterized by FTIR, surface functional groups (Boehm) and surface area analysis. Moreover, ACs were tested regarding adsorption capacity of methylene blue (MB), phenol and Cr+6 ions in aqueous medium. Higher total pore volume (0.62 cm³ g-¹), micropore volume (0.31 cm³ g-¹) and surface area (524.50 m² g-¹) were obtained in AC_ZnCl2, which was also the most effective in MB and phenol adsorption. AC_CuSO4 obtained high adsorption capacity for phenol and presented functional groups different from the other AC. AC_CO2 was the second with better adsorption performance for all pollutants.

ABSTRACT Currently, there is a little and sparse information about how the growing conditions influence the spatial variation of wood along the stem. Thus, the aim of this study was to compile the knowledge from literature in a manuscript for better understanding to what extent the growing conditions influence the spatial variation of wood properties in Eucalyptus plantations. The wood characteristics may present variations in their properties and can be caused by both genetic and environmental factors. However, how genetic and environmental factor acts on wood variation along the trunk is still unclear. Another point is that even with new genetic breeding programs, the mechanical properties of wood have not been considered in these programs, since the selection of new material is always based on the growing rate, cellulose and lignin content and wood density.

ABSTRACT This study aimed to evaluate the behavior of samples of juvenile and mature Eucalyptus cloeziana wood when subjected to the drying process, and the influence of the anatomy on that behavior. In order to do this, saturated specimens from this woods measuring 10 × 5 × 1 cm were subjected to drastic drying at 100 °C, where the drying rates and the end check scores in different steps of the process were obtained. The fibers and vessels morphology, initial moisture and basic density were analyzed to help understanding the data obtained in the drying test. The juvenile wood presented 26% higher drying rate and 21% smaller drying time, also 53% higher end check score. Smaller fibers length and fibers wall thickness, higher vessels frequency and smaller vessels diameter were associated with higher total drying rate and water adsorption, as well as with the higher end check score.

ABSTRACT The objective of this study was to establish the correlation between the size of the wood knots and the modulus of elasticity (MOE) and the compressive strength (Fc) in Eucalyptus wood. 156 Eucalyptus urophylla samples with knots were separated into 3 classes (small, medium and large knots), and samples were selected from the same tree and submitted to the parallel fiber compression test for MOE and Fc determination. There was a significant difference between the MOE and Fc of the smaller knot class (Class 1) and the other classes with larger knots (Classes 2 and 3). In general, the larger the knot, the greater the difference between the MOE and Fc. Wood with small knots (8.31 mm2) presents stiffness and strength statistically equal to wood free of defects. Eucalyptus wood stiffness is more sensitive to the presence of knots than the strength when compared to clear wood samples.

The heterogeneity of characteristics observed in the pith-bark direction within a log causes sawn pieces of wood have different behaviors during water removal. Understanding these differences is important for the industry regarding the possibility of classification of the lumber into juvenile wood and mature wood, facilitating the drying in separate loads. Thus, this study aimed to evaluate the behavior of juvenile and mature wood samples of Eucalyptus saligna when subjected to drastic drying. In order to do this, test specimens were submitted to drastic drying at 100°C to obtain the drying times, drying rates and dimensions of end checks. These data were applied in equations to obtain the parameters initial temperature, final temperature and drying potential, used in the elaboration of drying schedules. In juvenile wood we observed that the basic density was lower and the initial moisture content was higher. Mature wood showed a lower drying rate. Drying schedules were developed separately for juvenile and mature wood, the drying schedule for the latter considered milder than the drying schedule developed for juvenile wood.