Camila Lais Farrapo

Tree diversity of small forest fragments in ecotonal regions: why must these fragments be preserved?

Descriptions of biodiversity from ecotonal regions are lacking. This knowledge gap results from the difficulty of identifying elements from both biomes/domains and the advancement of human activities that generate small forest fragments. Here it is shown that small forest fragments in an ecotonal region have species richness and abundance in line with other inventories in preserved and non-preserved areas as well as composition and structure differentiated by the presence of species from both domains. The beta diversity among fragments reflects a high turnover supported by the formation of centers of dominance among the most abundant species. Finally, functional diversity favors the group that is tolerant of a wide range of environmental variables and is associated with faunal components. The results indicate that these fragments are important from a conservation standpoint because of the intersection of elements from threatened biomes, which must be managed coherently. However, Brazilian legislation is constantly modified and still allows anthropogenic changes that prevent the persistence of species.

Use of Castor Hull and Sugarcane Bagasse in Particulate Composites

Particulate composites can be manufactured using low-quality raw materials, thus presents the option of using various non-wood materials, including agricultural waste. This study aimed to evaluate the effect of using castor hull and sugarcane bagasse on the physico-mechanical properties of particulate composites. Particleboards were produced using raw materials such as Pinus oocarpa wood, castor hull (Ricinus communis), and sugarcane bagasse (Saccharum officinarum) in different proportions: 1) 100% P. oocarpa wood; 2) 100% castor hull; 3) 100% sugarcane bagasse; 4) 50% P. oocarpa wood and 50% castor hull; and 5) 50% P. oocarpa wood and 50% sugarcane bagasse. The produced panels had a nominal density of 0.70 g/cm3, 8% urea-formaldehyde adhesive, specific pressure of 3.92 MPa, temperature of 160°C, and pressing time of 8 min. The panels produced with sugarcane bagasse, with or without pine wood, showed better dimensional stability. The panels produced with sugarcane bagasse only or with castor hull only showed the lowest values of modulus of rupture and elasticity to the bending. However, despite these differences among the treatments, all treatments met the requirements of the EN 312 (2003) standard for internal use panels.

Effect of Association of Sugarcane Bagasse with Eucalyptus Wood on the Quality of Particleboard

Particleboard industries, which are progressively increasing in number, consume a significant amount of wood from planted forests, mainly from the Pinus and Eucalyptus genera. However, these panels can be produced from any lignocellulosic material that provides high mechanical strength and good physical characteristics. Accordingly, the waste generated by the Brazilian agribusiness industry is an alternative resource for manufacturing particleboards. The study aimed to evaluate the effect of the combination of sugarcane bagasse and eucalyptus wood on the physical and mechanical properties of particleboards. The panels were produced with sugarcane bagasse in the proportion of 0, 25, 50, 75, and 100% supplemented with E. urophylla. The panels were produced with 9% urea-formaldehyde adhesive, nominal density of 0.70 g/cm3, and with the pressing cycle of 160°C temperature, specific pressure of 3.92 MPa, and operation time of 8 min. The significance of the proportion of sugarcane bagasse on all physical and mechanical properties was evaluated. The panels with the combination of wood with sugarcane bagasse showed the lowest values in the physical properties and the highest values in the mechanical properties. Only panels prepared with 25% and 50% sugarcane bagasse met all the requirements of the marketing standards.

UMIDADE DE EQUILÍBRIO DE PAINÉIS OSB EM FUNÇÃO DA UMIDADE RELATIVA E DA TEMPERATURA AMBIENTE

The study aimed to obtain statistical models to estimate the equilibrium moisture content of OSB panels as a function of temperature and relative humidity of air, as well as evaluate the effect of some production variables on the equilibrium moisture content of the panels. The experimental design consisted of six processing conditions, three air temperature and six relative humidity of air. In the processing conditions, were evaluated three different thicknesses of the strand particles (0.4, 0.7 and 1.0 mm), two apparent densities of panels (0.65 and 0.90 g/cm³) and three levels of pressure in the pressing of the panels (40, 60 and 80 kgf/cm²). For each treatment four panels were produced with the wood of Pinus taeda and 6% of phenol formaldehyde adhesive. In the evaluation of the experiment was considered a completely randomized design arranged in a factorial triple 6 x 6 x 3, in order words, six production variables (processing conditions), three air temperatures (30, 40 and 50°C) and 6 relative humidity (40, 50, 60, 70, 80, 90%). The means were compared statistically by Scott-Knott test at the 5% level of significance. The modeling the equilibrium moisture content of OSB panels was performed with fit the multiple polynomial models for each treatment. Based on measurements of accuracy and the results can be concluded that: 1) it is recommended to use the model UEQ = β0 + β1UR + β2UR² + β3UR³ + β4Temp + e for indirect estimation of equilibrium moisture content of OSB panels 2) The temperature shows linear influence on the equilibrium moisture content of the panels, while the relative humidity of air shows behaving of third order polynomial, and the relative humidity of air affects more pronouncedly the equilibrium moisture content of OSB panels than the ambient temperature; 3) In respect of the effect of production variables, the pressing of pressure of 80 kgf/cm² and the increased the thickness of the strand particles to 1.0mm thick promoted trend of reductions in average of the equilibrium moisture content of OSB panels. But the increased density of the panel promoted the trend of increasing of equilibrium moisture content of OSB panels; and 4) The use of multiple polynomial models allows that are produced contours to obtain the values of equilibrium moisture content of OSB as a function of relative humidity and temperature of the place where the panel is exposed, standing out for its convenience of use.