ResumoEste trabalho avaliou as propriedades físicas e mecânicas de chapas de OSB usando madeiras de pinus, de cipreste e da mistura equitativa de dois clones de seringueira. Foram confeccionadas chapas de três camadas, na proporção face/miolo/face, de 1:2:1, massa específica de 0,75 g/cm 3 e resinas ureia-formaldeído (UF) e fenol-formaldeído (FF) nas proporções de 5% e 8%, com base na massa seca dos strands, sendo ensaiadas conforme ASTM D 1037 e comparadas com as normas CSA O437.0 e ANSI A.208.1. Os valores das propriedades mecânicas, exceto ligação interna, das chapas de cipreste usando a resina FF superaram as especificações das normas CSA O437.0 (classe O-2) e ANSI A.208.1, sendo de melhor desempenho a de 8% de adesivo. Em geral, as chapas apresentaram baixa estabilidade dimensional. O aumento no teor de resina levou ao melhor desempenho nas propriedades mecânicas e estabilidade dimensional. As chapas de seringueira apresentaram propriedades mecânicas acima do especificado pelas normas citadas, sendo que na ligação interna apenas aquelas coladas com 8% de FF atendeu à norma CSA O437.0. Palavras-chave: OSB; ureia-formaldeído; fenol-formaldeído; propriedades físicas e mecânicas. AbstractOriented strandboard made of pine, cypress and rubberwood. This research evaluated the physicalmechanical properties of oriented strandboards (OSB) using strands of pine, cypress and a mixture of two clones, of rubberwood. The ratio of face to core layer was 1:2:1. Boards measuring 450 x 450 x 13 mm were bonded with 5% and 8% of urea-formaldehyde (UF) and phenol-formaldehyde (FF) resins, based on the dry weight of the particles, with density of 0.75 g/cm 3 . The boards were evaluated according to ASTM D 1037 and compared with CSA O437.0 and ANSI A.208.1 standards. In general, as the resin level increased, mechanical and physical properties also improved, and panels with 8% FF resin showed the best performance. Cypress OSB made with FF resin showed higher mechanical properties, except internal bond than required by aforementioned standards. OSB panels were also dimensionally unstable since water absorption and thickness swelling values were very high. The mechanical properties of rubberwood OSB were higher than required by CSA O437.0 and ANSI A.208.1, except for internal bond, since only panels bonded with 8% of FF resin met the requirements of the CSA O437.0 standard.

Brazil has the largest continuous area of mangrove forests in the world, the Amazon Macrotidal Mangrove Coast (AMMC). The objective of the present study is to simulate the response of eastern Amazonian mangroves to sea-level rise, and to produce a vulnerability assessment for this section of the Brazilian coast. We used a spatially explicit model, based on cellular automata and Geographic Information System (GIS) to identify resistance patterns, migration and/or inundation of these mangroves for different events of sea-level rise (SLR). The simulation considers 90 elevation events from 0.00318 m to 0.2862 m according to an arithmetic progression of reason 0.00318 m for the time interval from 2010 to 2100. The adopted SLR rate was 3.18 mm / year (0.00318 m / year), this rate corresponds to an average of sea elevation values observed for the Brazilian coast during the mid-twentieth century and early twenty-first century. At the end of the simulation (year 2100), the original mangrove area (4,180 km 2) was reduced to 2,916 km 2 , representing a loss of 30.24%. Our simulation also showed significant landward migration of the mangroves, and the modeled loss of the original mangrove area was compensated by a net addition of 301 km 2 of new mangroves inland, a net increase of 7.2% in the total mangrove area (4,481 km 2 in 2100). These results suggest that mangrove forests in the AMMC can present a pattern of area increase and migration to the continent from the projected SLR. These findings can help the identification of migration corridors for the Amazonian mangroves and the development of adaptation strategies in face of impending SLR.