ABSTRACT Background: Patauá (Oenocarpus bataua Mart.) is a palm tree belonging to the botanical family Arecaceae that occurs throughout the Amazon. Like açaí, an edible pulp is extracted from its fruits, remaining a fiber-rich waste. Revealing the potential of such raw or thermochemically modified fibers for producing bioproducts is a novelty in the literature. Therefore, this work aimed to characterize patauá fibers in natural and alkali-treated conditions to support future bioproduct applications. Alkaline treatments were performed under mechanical stirring combining two NaOH levels (5 and 10%) and two temperatures (80 and 100°C). Morphological characterization was performed by light microscopy and scanning electron microscopy (SEM). The contents of the structural and non-structural chemical components were determined, and chemical groups were evaluated by Fourier-transform infrared spectroscopy (FTIR). The physical characterization included moisture content, apparent density, and water absorption tests. Results: The macerate revealed short fibers with typical elongated morphology, mean cell wall thickness (4.10 µm) greater than the mean lumen width (3.01 µm), and mean length of 445 µm. The alkaline treatments partially individualized the fibers from bundles, cleaned extractives from the surface, and unblocked superficial pits by removing silica-rich structures. They substantially removed non-cellulosic components, but FTIR showed condensed lignin exposed on the fiber surface. Density and water uptake increased concerning natural fibers. Patauá’s short length and susceptibility to modification through thermochemical treatments that concentrated cellulose up to 50% indicated great potential for developing composites and nanofibers. Regardless of the NaOH content, 100°C was more efficient in concentrating cellulose. Conclusion: Patauá fibers have unique natural characteristics. They occur as flatted fiber bundles, have silicon-rich structures obstructing their superficial pits, and comprise more lignin than cellulose.

ABSTRACT Background: Many gaps in the copaifera oleoresin yield remain unfulfilled, preventing the sustainable management of this valuable non-timber forest product. This work aimed to characterize a natural Copaifera reticulata population in the Amazon rainforest, test different positions and depths in the trees to flow oleoresin, and analyze changes in the productiveness between two harvests ten months-spaced. The study was conducted in a Brazilian rainforest area at the Jari Ecological Station (ESEC) in 2017 and 2018, including 26 trees. Results: The diametric and height distributions evidenced light-demanding and mostly medium-class-diameter trees. The annual increment (0.45 ± 0.003 cm/year) was average, while the occurrence was rare. The area hosts yielding and unyielding trees, providing an average oleoresin production of 603.60 mL/tree. Oleoresin only flowed by reaching the inner heartwood or the pith. Oleoresin was not fully replenished after ten months, but the first drilling stimulated some unyielding trees to deliver it later. Collecting should focus on medium-diameter trees. Conclusion: The growth and distribution behaviors may challenge Copaifera’s sustainable management, which depends on the individual tree mechanisms to provide and replenish the oleoresin.

ABSTRACT Background: During de-pulping of açai (Euterpe oleracea) for juice production in the Amazonia, large amounts of fibrous waste are daily discarded, a promising substrate for production of high-value cellulose nanofibrils. Therefore, this study sought to evaluate the modifications of açai surface fibers submitted to chemical pretreatment steps and compare the quality of nanostructured films produced with different cycles of mechanical nanofibrillation. Results: A 2-hour pretreatment (at 5% of NaOH) followed by two NaOH/H2O2 bleaching steps resulted in fibers with increased length and reduced diameter compared to raw fibers while preserving fiber integrity and cellulose I structure. The increase of fibers’ grinding cycles from 3 (minimum to gel point) to 21 (maximum suspension thickness) resulted in nanofibril films with higher crystallinity properties, uniform thickness, compacted morphology, and smoother surface. Nanofibril films formed after different numbers of passages exhibited similar mechanical strength, but distinct barrier properties. Conclusion: Açaí waste films produced with fibers submitted to 3 grinding cycles can be recommended for packaging applications that demand easily dissolving, such as instantaneous food. Oppositely, açaí fibers subjected to 21 cycles in grinder provide films suitable for water-resistant packaging, ideal for secondary coatings of papers and paperboards.

Resumo Apesar da importância social, cultural e econômica para a Região Amazônica, o potencial energético da Mauritia flexuosa, popularmente conhecida como buriti, ainda não foi explorado para ampliar as possibilidades de uso dessa espécie pelas comunidades locais. Assim, o objetivo deste trabalho é comparar o potencial dos tecidos que compõem o pecíolo de Mauritia flexuosa para combustão e carbonização. O miolo e casca do pecíolo foram separados e caracterizados por composição química (extrativos removíveis por água e totais, lignina e cinzas), umidade base úmida, composição imediata (teores de materiais voláteis, carbono fixo e cinzas), densidade básica, poder calorífico superior e análise termogravimétrica em atmosfera inerte de N2. Os dois tecidos do pecíolo de Mauritia flexuosa apresentaram vantagens para finalidades bioenergéticas, como: baixo teor de cinzas (≤ 2%), além de teor de carbono fixo (≈ 18%) e poder calorífico superior (≈ 18 MJ kg-1) adequados. Para miolo e casca, os teores de lignina (19 e 28%, respectivamente), extrativos (8,9 e 5%, respectivamente), e densidade básica (0,041 e 0,267 g cm-3, respectivamente) diferiram significativamente. Contudo, a composição imediata dos tecidos não foi influenciada por essas diferenças, ao contrário do poder calorífico e densidade energética. O comportamento termogravimétrico demonstrou taxa de degradação superior e rendimento final em massa inferior (7%) para o miolo em relação à casca. A casca apresentou melhor qualidade para combustão e carbonização em comparação ao miolo. Esse resultado é vantajoso para as comunidades extrativistas da Amazônia, pois a casca é um resíduo do processamento do pecíolo para obtenção do miolo, destinado à produção de artesanatos. Pela baixa densidade básica, o miolo é mais indicado para torrefação, densificação, pirólise para geração de bio-óleo e produção de filtros naturais e carvões ativados do que para combustão direta e carbonização.

Abstract Despite its social, cultural and economic importance for the Amazon region, the energy potential of Mauritia flexuosa, popularly known as buriti, has not yet been explored in order to expand the possible uses of this species by the local communities. Therefore, the aim of this work was to compare the tissues that comprise the petiole of Mauritia flexuosa for combustion and carbonization. The petiole core and bark were separated and characterized by chemical composition (total and water-soluble extractives, lignin, and ashes), moisture content (based humid mass), proximate composition (contents of volatile matter, fixed carbon, and ash), basic density, higher heating value, and thermogravimetric analysis in N2 inert atmosphere. The two tissues from the Mauritia flexuosa petiole presented advantages for bioenergetic purposes, such as low ash content (≤ 2%) and higher heating value (≈ 18 MJ kg-1), in addition to suitable fixed carbon (≈ 18%). For the core and husk, the lignin contents (19 and 28%, respectively), extractives contents (9 and 5%, respectively), and basic density (0.041 and 0.267 g cm-3, respectively) significantly differed. However, the proximate composition of the tissues was not influenced by such differences, unlike the higher heating value and energy density. The thermogravimetric behavior showed higher degradation ratio and lower final mass yield (7%) for the core in comparison to the husk. The husk showed better quality for combustion and carbonization in comparison to the core. This is an advantageous result for the extractive activities of Amazonian communities because the husk is a waste from the petiole processing in order to obtain the core for handcraft. Due to the low basic density, the core can be noted for its use in torrefaction, densification, pyrolysis for the production of bio-oil and production of natural filters and activated charcoals, rather than direct combustion and carbonization.

ABSTRACT Currently, there is a lack of studies on the correct utilization of continuous distributions for dry tropical forests. Therefore, this work aims to investigate the diameter structure of a brazilian tropical dry forest and to select suitable continuous distributions by means of statistic tools for the stand and the main species. Two subsets were randomly selected from 40 plots. Diameter at base height was obtained. The following functions were tested: log-normal; gamma; Weibull 2P and Burr. The best fits were selected by Akaike's information validation criterion. Overall, the diameter distribution of the dry tropical forest was better described by negative exponential curves and positive skewness. The forest studied showed diameter distributions with decreasing probability for larger trees. This behavior was observed for both the main species and the stand. The generalization of the function fitted for the main species show that the development of individual models is needed. The Burr function showed good flexibility to describe the diameter structure of the stand and the behavior of Mimosa ophthalmocentra and Bauhinia cheilantha species. For Poincianella bracteosa, Aspidosperma pyrifolium and Myracrodum urundeuva better fitting was obtained with the log-normal function.

RESUMO O objetivo deste trabalho foi avaliar a qualidade de painéis particulados produzidos com diferentes formulações, variando percentagens de adesivo e casca de arroz (Oryza sativa L.) adicionadas à madeira de Cunninghamia lanceolata. Três teores de adesivo (6, 9 e 12%) e três proporções de casca de arroz (25, 50 e 75%) foram combinados resultando em 9 formulações. Para analisar a influência de cada matéria-prima na qualidade final dos painéis, sua composição química foi determinada de acordo com os teores de extrativos, componentes minerais, lignina e holocelulose. Os painéis aglomerados foram avaliados pelas seguintes propriedades físicas e mecânicas: absorção de água (AA), inchamento em espessura (IE), ligação interna (LI), compressão paralela (CP), módulo de elasticidade (MOE) e módulo de ruptura (MOR) na flexão estática. Os valores médios das propriedades físicas e mecânicas demonstraram que menores teores de casca de arroz e maiores teores de adesivo ocasionaram melhor desempenho dos painéis. O baixo teor de lignina e alto teor de cinzas da casca de arroz influenciaram negativamente a qualidade dos painéis. Dentre as formulações avaliadas, painéis com inclusão de 25% de casca de arroz e 9% de ureia-formaldeído apresentaram os melhores resultados. Os painéis produzidos neste trabalho são alternativas potenciais para aplicações gerais em condições secas que não demandem alta resistência mecânica. No entanto, o processo e as formulações necessitam ser ajustados para aplicações estruturais mais exigentes.

ABSTRACT This work aimed to evaluate the quality of particleboards made with different formulations, varying adhesive content and rice husk (Oryza sativa L.) proportions added to Cunninghamia lanceolata wood. Three adhesive contents (6, 9 and 12%) and three proportions of rice husk added to wood (25, 50 and 75%) were combined resulting in 9 formulations of particleboards. In order to analyze the influence of each raw material in the final quality of the boards, their chemical composition was determined, including extractive, ash, lignin and holocellulose contents. Regarding the particleboards, the following physical and mechanical properties were evaluated: water absorption (WA), thickness swelling (TS), internal bonding (IB), parallel compression (PC), modulus of elasticity (MOE) and modulus of rupture (MOR) in static bending. For both mechanical and physical properties, average values showed that lower rice husk proportions and higher adhesive contents induced to better performance. Low lignin and high ash contents found in rice husks negatively influenced particleboard quality. Among the formulations tested, the inclusion of 25% of rice husk and 9% urea-formaldehyde presented the best results. Particleboards produced in this work are potential alternatives for general applications in dry conditions that do not require high mechanical resistance. Nevertheless, the process and formulations need to be adjusted in order to reach the requirements for more demanding structural applications.

This work aimed to investigate the feasibility of using and mixing Toona ciliata, Eucalyptus urophylla/grandis and Pinus oocarpa woods in OSB production. Three one- species and four mixed-species combinations were compared. Layer structure varied by positioning different wood species in the surface and core of the panels. Phenol- formaldehyde (PF) adhesive was applied at 9% for all OSB panels. Three-layer mats with mass proportion of 25/50/25% for surface/core/surface were produced. Pressing time was 8 min, under a 4 MPa pressure and temperature of 180°C. Physical and mechanical properties were evaluated and compared to EN (300) commercialization standard. Most OSB panels did not fully attain such requirements. OSB panels made with Eucalyptus urophylla/grandis and Pinus oocarpa woods have potential to be commercialized as OSB/1 and OSB/2 types, respectively. Among panels made with T. ciliata wood, those produced with this species in the surface and Eucalyptus urophylla/grandis wood in the core met the requirements established for OSB/1 commercialization. Eucalyptus wood has great potential to substitute Pinus wood in OSB production. The utilization of T. ciliata wood for OSB production decreased mechanical performance, but remarkably enhanced water resistance properties.

Objetivou-se, neste trabalho, avaliar, por meio da análise de componentes principais, a qualidade da madeira de Coffea arabica L. em diferentes variedades e sistemas de cultivo como fonte de bioenergia. Foram utilizadas madeiras provenientes de três sistemas de cultivo (natural, convencional e orgânico) e de duas variedades distintas (Mundo Novo e Catuaí), totalizando seis tratamentos. Foram quantificados os teores dos componentes elementares (C, H, N, S e O), de cinzas, lignina, extrativos totais e holocelulose, a densidade básica, o poder calorífico superior, o poder calorífico inferior, o poder calorífico superior e inferior volumétricos das madeiras analisadas. Foi realizada a análise estatística multivariada de componentes principais. Os escores das componentes principais de interesse foram determinados como forma de dividir as madeiras em grupos. O grupo I foi composto pela madeira do cafeeiro orgânico Mundo Novo e natural Mundo Novo; o grupo II pelo orgânico Catuaí, e o grupo III pelas madeiras dos cafeeiros convencional Mundo Novo, natural Catuaí e convencional Catuaí. Os resíduos madeireiros da espécie Coffea arabica L. apresentaram grande potencial para o uso energético, com destaque para as madeiras provenientes do sistema de cultivo convencional e da variedade Catuaí. As madeiras do grupo III se destacaram em decorrência dos elevados valores de poder calorífico volumétrico, densidade básica, teor de lignina e poder calorífico superior. Entretanto, as madeiras desse grupo apresentaram elevado teor de nitrogênio.

This work aimed to evaluate, through principal component analysis, the quality of Coffea arabica L. wood obtained from different growth systems and varieties as a source of bioenergy. Wood from three different growth systems (natural, conventional and organic) and two different varieties (Mundo Novo and Catuaí) were used, totalizing six treatments. The contents of elementary components (C, H, N, S and O), ash, lignin, total extractives and holocellulose, basic density, the higher heating value, the lower heating value, as well as the lower and higher volumetric heating values of the analyzed woods were quantified. Principal components multivariate statistical analyses were conducted. The scores of the principal components of interest were determined as a way to divide the woods into groups. Group I was composed by the wood from the organic coffee "Mundo Novo" and natural "Mundo Novo"; Group II by the organic "Catuaí", and Group III by the wood from convencional "Mundo Novo", natural "Catuaí" and convencional "Catuaí". Wood residues from the species Coffea arabica L. showed great potential for energetic use, especially the woods from the conventional systems and the "Catuaí" Variety. Woods from Group III stood out, due to the high volumetric heating values, basic density, lignin content and higher heating value. However, the woods of this group showed high nitrogen content.

Objetivou-se, neste trabalho, avaliar a qualidade do encolamento de partículas "strand" e a influência desse processo na qualidade final da colagem em painéis OSB. Realizou-se a mensuração das dimensões e determinação da massa de 658 partículas antes e após o processo de encolamento. As variáveis gramatura (g.m-2) e a quantidade efetiva de adesivo aplicado (%) foram avaliadas. Aplicaram-se os teores de 6, 9 e 12 % de adesivo fenol-formaldeído em partículas de Pinus oocarpa e Eucalyptus grandis. Foi realizado o teste de tração perpendicular nos painéis produzidos. O processo de encolamento de partículas "strand" em laboratório é heterogêneo, o que dificultou analisar a influência das variáveis de processamento sobre a quantidade efetiva de adesivo aplicado e gramatura. Foi verificado que painéis OSB produzidos com a espécie Pinus oocarpa apresentaram menor gramatura de partículas em relação aos painéis de Eucalyptus grandis. Esse resultado foi atribuído a menor densidade básica da madeira de Pinus oocarpa. Observou-se que maiores gramaturas na partícula estão, positivamente, relacionadas com a resistência à tração perpendicular.

This work aimed to evaluate the quality of strand particles gluing and its influence on the final bonding quality in OSB panels. The measurement of the dimensions and determination of the mass of 658 particles were made before and after the gluing process. The variables glue amount (g.m-2) and effective amount of adhesive applied (%) were evaluated. Phenol-formaldehyde adhesive was applied at 6, 9 and 12% contents in Pinus oocarpa and Eucalyptus grandis particles. Perpendicular tension strength test was conducted in the panels produced. The gluing process in laboratorial conditions is heterogeneous, which hinders the analysis of the influence of the processing variables on the effective amount of adhesive applied and glue amount. It was verified that OSB panels made from Pinus oocarpa species presented lower glue amount per particle in relation to Eucalyptus grandis species. This result was attributed to the lower basic density of Pinus oocarpa wood. Increases in glue amount of particles are related to increases in perpendicular tension strength.

Conduziu-se, este trabalho, com o objetivo de testar a eficiência da equação de Nelson na estimativa da umidade de equilíbrio desse tipo de material e propor um modelo para a determinação da umidade dos painéis em função da umidade relativa do ar, bem como avaliar os efeitos de algumas variáveis de processo na umidade de equilíbrio de painéis OSB (Oriented Strand Board). Amostras com dimensões de 25 x 25 mm foram colocadas em câmara de climatização, onde permaneceram a uma temperatura constante de 30ºC e tiveram suas massas determinadas, quando estabilizadas nos teores de umidade relativa do ar de 40, 50, 60, 70, 80 e 90%. Pelos resultados obtidos, pode-se concluir que: a equação de Nelson tem a tendência de subestimar os valores de umidade do painel; o modelo polinomial ajustado com base apenas na umidade relativa do ar apresentou grande potencial de utilização; não houve efeito das variáveis densidade do painel, densidade básica da madeira, tipo de colchão e temperatura de prensagem sobre os valores médios de umidade de equilíbrio na dessorção 1, adsorção e dessorção 2, apesar de comportamentos distintos terem sido observados para as isotermas dos tratamentos.

This work aimed to verify the efficiency of Nelson's equation to estimate equilibrium moisture content of this material and provide a model for determination of moisture content of panels based on air relative moisture content, as well as to evaluate the effect of some processing variables on the equilibrium moisture content of OSB (Oriented Strand Board) panels. The 25 x 25 mm samples were put in an acclimation room where they were kept at 30ºC and had their mass determined after stabilization at the relative air moisture contents of 40, 50, 60, 70, 80 and 90%. By the results obtained it was possible to conclude that: Nelson's equation tended to underestimate moisture values of the panel; the polynomial model adjusted based on the relative moisture of the air presented great potential to be used; although different behavior may be observed for the isotherms of treatments, there was no significant effect of the variables panel density, wood basic density, mat type and pressure temperature on mean equilibrium moisture content in desorption 1, adsorption and desorption 2.

Neste trabalho, objetivou-se comparar a resistência das madeiras de cedro australiano (Toona ciliata) e pinus (Pinus sp.) e de painéis aglomerados produzidos com essas espécies ao ataque do cupim de madeira seca Cryptotermes brevis, bem como quantificar a mortalidade dos insetos. Foram colocados 30 pseudo-operários em placas de Petri de acrílico de 9,5 cm de diâmetro, contendo as amostras (1,5 x 1,5 x 0,5 cm) e folhas de algodão posicionadas sobre as tampas perfuradas umedecidas diariamente com 5 ml de água. As placas foram acondicionadas em BOD (Biological Oxygen Demand) a 24±5ºC e escotofase de 24 h. Uma amostra testemunha sem fonte de alimentação foi incluída no bioensaio. O cálculo do índice de deterioração (ID) das amostras e a avaliação da mortalidade foram realizados após 60 dias. Os cupins da amostra testemunha apresentaram mortalidade maior em relação aos cupins dos demais tratamentos, os quais não se diferenciaram entre si. A madeira de Toona ciliata foi mais resistente ao ataque de Cryptotermes brevis em relação à madeira de Pinus sp. Os índices de deterioração médios foram de 1,74% e 6,62% para essas madeiras respectivamente. O índice de deterioração médio do painel produzido com 100% de Toona ciliata (ID=1,58%) foi similar ao índice de deterioração do painel produzido por essa mesma espécie em mistura com Pinus sp. (ID=1,87%).

The aim of this work was to compare the resistance of Australian red cedar (Toona ciliata) and pine (Pinus sp.) woods and particleboards made from these species to dry-wood termite Cryptotermes brevis attack, as much as to quantify the mortality of the insects. 30 termite pseudo-workers were put in each 9,5 cm-diameter Petri dishes containing the samples (1,5 x 1,5 x 0,5 cm) and cotton sheets positioned on the perforated covers, daily moisturized with 5 ml of water. The dishes were maintained in BOD (Biological Oxygen Demand) at 24±5 ºC and 24 h of escotophase. A control sample without any feed source was included in the bioassay. The deterioration index (ID) and mortality of the insects were evaluated after 60 days. Termites from the control sample presented higher termite mortality than the other treatments, which did not differ among each other. Toona ciliata wood was more resistant than Pinus sp. wood to Cryptotermes brevis attack. The average deterioration indexes were 1.74% and 6.62% respectively for those woods. The average deterioration index of the panels made with 100% Toona ciliata (ID=1.58%) was similar to the deterioration index of particleboards made with this specie mixed with Pinus sp. (ID=1.87%).

O Brasil é um dos maiores produtores de banana do mundo e, consequentemente, gera uma grande quantidade de resíduos provenientes dessa cultura, os quais poderiam ser aproveitados na produção de aglomerados. No presente trabalho, objetivou-se avaliar o efeito de diferentes tratamentos químicos nas partículas de pseudocaule da bananeira Musa sp. em suas propriedades químicas e físicas (densidade básica), além da influência desses tratamentos nas propriedades físicas e mecânicas de painéis aglomerados produzidos com o mesmo material. Foram realizados 5 tratamentos nas partículas, sendo: 1) sem tratamento (testemunha); 2) ácido acético 2% ; 3) NaOH 0,5 %, 4) acetona (1/1 em volume/volume); e 5) água. Os painéis produzidos foram de média densidade (0,70 g/cm³), encolados com o adesivo ureia-formaldeído a 12% (em relação à massa de partículas). O ciclo de prensagem utilizado foi 4 MPa de pressão, a uma temperatura de 160º C, por um período de 8 min. Os resultados obtidos indicaram que todos os tratamentos químicos realizados nas partículas de pseudocaule da bananeira afetaram a composição química do material. A densidade básica das partículas do pseudocaule foi de 0,10 g/cm3 e o tratamento com NaOH foi o único que afetou essa propriedade, ocasionando seu aumento para 0,13 g/cm3. Os painéis produzidos com as partículas sem tratamento (testemunha), e com as tratadas com ácido acético foram os que apresentaram menores valores de absorção de água e inchamento em espessura após 2 e 24 h de imersão. As propriedades mecânicas de todos os painéis produzidos ficaram abaixo do mínimo recomendado pela norma CS 236-66 (COMMERCIAL STANDARD - CS, 1968).

Brazil is one of the major banana producers in the world, and consequently generates a great amount of residues from this crop, which could be utilized in particleboard production. The present work aimed to evaluate the effect of different chemical treatments of the particles of Musa sp. pseudostem, on their chemical and physical properties (basic density), and on the physical and mechanical properties of the particleboards produced with the same material. Five treatments were applied to the particles: 1) without treatment (control); 2) 2% acetic acid; 3) 0.5% NaOH; 4) acetone (1/1 in volume/volume); and 5) water. Panels with medium density were produced (0.70 g/cm³), bonded with 12% (in relation to the particle mass) of urea-formaldehyde adhesive. The pressing cycle was conducted at 160º C, under 4 MPa, during 8 min. The results obtained indicated that the chemical treatments performed in the particles of banana tree pseudostem affected their chemical composition. The basic density of the particles was 0.10 g/cm³, and only the NaOH treatment led to its increase for values around 0.13 g/cm3. The panels produced with particles without treatment (control) and particles treated with acetic acid presented the lowest values of water absorption and thickness swelling after 2 and 24 h of immersion. Mechanical properties of all the panels produced were below the minimum recommended by the standard CS 236-66 (COMMERCIAL STANDARD - CS, 1968).

RESUMO Na avaliação de resíduos lignocelulósicos para a produção de bioenergia é necessário considerar as várias características e propriedades que podem ser correlacionadas. Este fato demanda o emprego de diversas técnicas de análise multivariada que possibilitem a avaliação dos fatores energéticos mais relevantes. O objetivo deste trabalho foi aplicar as análises de agrupamento e componentes principais na seleção e avaliação de resíduos lignocelulósicos visando à produção de bioenergia. Foram utilizados 8 tipos de biomassa residual, dos quais foram determinados os teores dos componentes elementares (C, H, O, N, S), os teores de lignina, extrativos totais e cinzas, a densidade básica e o poder calorífico superior e inferior. As duas técnicas multivariadas empregadas para a avaliação e seleção de resíduos lignocelulósicos para a produção de energia foram eficientes, sendo observadas similaridades entre os grupos de biomassa formados por elas. Pela interpretação da primeira componente principal obtida, criou-se um índice de desempenho global para avaliar a viabilidade do aproveitamento energético da biomassa. A interpretação da segunda componente principal permitiu um contraste entre os teores de nitrogênio e enxofre e o teor de oxigênio.

ABSTRACT The evaluation of lignocellulosic wastes for bioenergy production demands to consider several characteristics and properties that may be correlated. This fact demands the use of various multivariate analysis techniques that allow the evaluation of relevant energetic factors. This work aimed to apply cluster analysis and principal components analyses for the selection and evaluation of lignocellulosic wastes for bioenergy production. 8 types of residual biomass were used, whose the elemental components (C, H, O, N, S) content, lignin, total extractives and ashes contents, basic density and higher and lower heating values were determined. Both multivariate techniques applied for evaluation and selection of lignocellulosic wastes were efficient and similarities were observed between the biomass groups formed by them. Through the interpretation of the first principal component obtained, it was possible to create a global development index for the evaluation of the viability of energetic uses of biomass. The interpretation of the second principal component allowed a contrast between nitrogen and sulfur contents with oxygen content.

Neste trabalho, objetivou-se avaliar o desempenho físico-mecânico de painéis de lâminas paralelas (LVL) produzidos com diferentes composições de espécies tropicais amazônicas e Pinus oocarpa. Foram utilizadas três espécies tropicais: Cordia goeldiana Huber. (Freijó), Parkia gigantocarpa Ducke (Faveira) e Brosimum parinarioides Ducke (Amapá doce). Para comparação, foi utilizada madeira de Pinus oocarpa proveniente de plantio experimental. Três tipos de combinações de lâminas foram avaliados: (i) uma espécie, (ii) combinação das três espécies amazônicas e (iii) combinação de espécies amazônicas com Pinus oocarpa. Avaliou-se também a velocidade de propagação acústica com o stress wave timer para a determinação do módulo de elasticidade dinâmico (MOEd), que foi correlacionado com o módulo de elasticidade estático (MOEe) do painel. Os painéis produzidos com espécies da Amazônia apresentaram menor absorção de água total em relação aos painéis de Pinus oocarpa. Para as propriedades mecânicas, a menor resistência foi verificada para painéis de faveira. Não houve diferença estatística entre os painéis para a resistência ao cisalhamento na linha de cola. O stress wave timer poderia ser utilizado para predição do MOEe a partir do MOEd.

This work aimed to evaluate the physical-mechanical performance of laminated veneer lumber (LV) produced with different compositions of tropical Amazonian species and Pinus oocarpa. Three tropical species were used: Cordia goeldiana Huber. (Freijó), Parkia gigantocarpa Ducke (Faveira) and Brosimum parinarioides Ducke (Amapá doce). For comparison, Pinus oocarpa wood obtained from an experimental stand was used. Three types of veneer combination were evaluated: (i) one species; (ii) the three Amazonian species combination and (iii) combination of Amazonian species with Pinus oocarpa. The acoustic propagation velocity was also evaluated with the stress wave timer for correlation between dynamic modulus of elasticity (MOEd) and static modulus of elasticity (MOEs) of the panel. Panels produced with Amazonian species presented lower water absorption than Pinus oocarpa panels. Regarding the mechanical properties, the lowest strength was verified for "faveira" panels. There was no statistical difference among panels in glue line shear strength. The stress wave timer could be used for prediction of MOEs by using MOEd.

Studies concerning the production of particleboards with sugarcane bagasse as an alternative fibrous material have been carried out as an attempt to provide a sustainable and viable destination for this residue. This work aimed to evaluate the influence of several processing variables related to the microstructure of sugarcane bagasse particleboards (mat type, adhesive type and adhesive content) on their permeability and water sorption properties. Air permeability data was collected by the rotameter method. Superficial air permeability (kg), Darcian constant (k1) and non-Darcian constant (k2) were measured. kg was related to sorption behavior of the particleboards. 1-layer particleboards presented significantly higher kg values than the 3-layer particleboards. In general, adhesive type, position and content did not influence kg of particleboards. However, these processing variables influenced interactions between fluid and material and tortuosity of the porous media. Particleboards produced with urea-formaldehyde with high kg presented higher water absorption and thickness swelling after 24 hours. Such relations were not observed in particleboards produced with melamine-urea-formaldehyde.