Among the parameters used in the biomass carbonization process, the heating rate is one of the most important. The objective of the present work was to assess the influence of different heating rates on the chemical composition of wood vinegar (WV) from two wood species. Dried disks of Eucalyptus grandis and Mimosa tenuiflora wood were used as raw material. Carbonization runs were carried out in a laboratory muffle furnace at three heating rates (0.7, 1.0 and 1.4 °C/min), with 10 runs at each heating rate, reaching 450 °C. Yields of charcoal, pyrolysis liquids and gases were determined for all carbonization conditions. Crude pyrolysis liquid from each wood species and each heating rate was bi-distilled, yielding purified WV samples. These samples were extracted with ethyl acetate and the organic fraction was analyzed by gas chromatography-mass spectrometry to obtain qualitative and semi-quantitative data. Results showed that lower heating rates produce higher yields of charcoal, while higher heating rates lead to higher yields of pyrolysis liquids and gases. Totals of 57 and 42 chemical compounds were identified in the WV of Eucalyptus and Mimosa, respectively, divided into the following groups: alcohols, ketones, furans and pyrans, and phenolic compounds. In general, higher heating rates led to greater contents of furans and pyrans and lower concentrations of phenolic compounds.

A vegetação da Caatinga é explorada para energia, mas existem poucos estudos sobre as relações entre as características da madeira e seu potencial energético. Assim, o objetivo desta pesquisa foi relacionar as características da madeira e do carvão vegetal das espécies catingueira (Poincianella pyramidalis) e pau-d'arco (Handroanthus impetiginosus). Foram abatidas cinco árvores por espécie e retirados toretes de 30 cm de comprimento a 0 (base), 25, 50, 75 e 100% da altura comercial da árvore. Esse material foi utilizado para determinação das características da madeira e do carvão vegetal. A catingueira produziu maior rendimento em carvão vegetal que o pau-d'arco; no entanto, a madeira desta espécie apresentou melhores características para fins energéticos. As duas espécies apresentaram relações entre as características anatômicas, físico-químicas e energéticas diferentes. O conhecimento da disparidade entre as relações das características da madeira possibilita o uso mais adequado da mesma para fins energéticos.

Pinus forests are the second most planted in Brazil and the wood obtained from them is mainly used as structural elements in the civil construction sector. The Brazilian standard that deals with calculations of wooden structures projects recommends the use of wood in the range of 10% to 20% of moisture content. Thus, this study aimed to present an investigation about the influence of moisture content on the static modulus of elasticity (MOEst) of wooden beams by transverse vibration tests. The MOEst was evaluated by static bending tests and transverse vibration tests for various moisture content. The transverse vibration test was performed in a free condition using an accelerometer and an impulse hammer, and the dynamic modulus of elasticity (MOEd) was determined from the frequency of the first bending vibration mode. A total of 20 wooden beams were obtained from freshly cut Pinus spp. logs with initial high moisture content were used, with nominal dimensions of 5 cm × 10 cm × 200 cm (thickness × width × length). It was observed that the MOEd is also affected by moisture content according to the non-linear regression model. There were significant changes in the dynamic modulus of elasticity (MOEd) for the moisture contents (M) below 25% (near the fiber saturation point - FSP).

This research aims to evaluate the physico-mechanical properties of wood-plastic composites produced with recycled polyethylene terephthalate, high-density polyethylene, low-density polyethylene and polypropylene, and sawdust from the following species: Pinus caribaea, Pinus cubensis, Cedrela odorata, Talipariti elatum and Eucalyptus sp. Composites were obtained by extrusion with dimension of 1,000 × 250 × 16 mm (length × width × thickness), through six treatments. The following physico-mechanical properties were evaluated: density, moisture content, water absorption and thickness swelling, compression, static bending and traction. Treatment 6 obtained the best results, with 1,060 kg m-3 density, 5.23% moisture content, 0.32% water absorption, and 0.18% thickness swelling. Compressive strength was 138.10 MPa, static bending 18.53 MPa, and traction 29.4 MPa. The technology developed has prospects for large-scale production.

Esta pesquisa objetivou avaliar a eficiência dos óleos de nim (Azadirachta indica) e de mamona (Ricinus communis) na melhoria da resistência da madeira de sumaúma (Ceiba pentandra) ao térmita xilófago Nasutitermes corniger em ensaio de preferência alimentar. Os óleos das sementes de nim e de mamona foram extraídos com álcool etílico absoluto e empregados no preparo das soluções preservativas. Amostras de madeira com dimensões de 2,0 x 10,16 x 0,64 cm (radial x longitudinal x tangencial) foram tratadas para atingir uma retenção nominal de 10 a 16 kg de solução por metro cúbico de madeira, sendo parte das amostras tratadas submetida ao envelhecimento (volatilização ou lixiviação). As amostras tratadas foram submetidas à ação de cupins em ensaio de preferência alimentar. Os referidos óleos pouco contribuíram para a melhoria da resistência da madeira de sumaúma ao cupim testado. Entre as soluções testadas, o óleo de mamona puro foi o mais eficiente. O envelhecimento das amostras pouco influenciou na resistência da madeira. Os óleos de nim e de mamona puros e suas soluções, mesmo apresentando algum efeito de repelência aos cupins, não evidenciaram efeito duradouro, indicando que esses produtos não devem ser empregados no tratamento da madeira com o objetivo de melhorar sua resistência a cupins xilófagos.