José Reinaldo Moreira da Silva

Melhoramento genético das propriedades do carvão vegetal de Eucalyptus

Os objetivos deste trabalho foram estimar os parâmetros fenotipicos, e genotipicos, e ganhos geneticos para as propriedades do carvao vegetal e selecionar clones de Eucalyptus, por meio de caracteristicas do carvao vegetal, visando a otimizacao da sua producao e qualidade. Foram utilizados nove clones hibridos de Eucalyptus cultivados no Municipio de Taiobeiras, Norte de Minas Gerais. O delineamento experimental utilizado foi o inteiramente casualizado, com tres repeticoes. Os parâmetros fenotipicos e geneticos foram estimados a partir dos quadrados medios das caracteristicas avaliadas no carvao vegetal. Estimou-se o ganho genetico de todas as caracteristicas que apresentaram significância. O efeito de clone foi significativo quanto ao rendimento gravimetrico do carvao, rendimento em carbono fixo e densidade basica relativa aparente do carvao. O ganho genetico previsto para o rendimento gravimetrico do carvao foi de 4,51% na selecao dos clones FGA-30 e FGA-49 e de 4,16% para o rendimento em carbono fixo na selecao dos clones FGA-30 e I-249. Para densidade basica relativa aparente, o ganho genetico foi de 0,03% na selecao dos clones FGA-49 e FGA-34.

Cell wall biochemistry of sapodilla (Manilkara zapota) submitted to 1-methylcyclopropene

Sapoti (Manilkara zapota) e um fruto climaterico que amadurece rapidamente apos a colheita e os estudos acerca da extensao de sua vida util pos-colheita sao principalmente restritos ao uso de baixa temperatura e atmosfera modificada. Este trabalho avaliou a influencia do 1-metilciclopropeno (1-MCP) sobre o amolecimento e bioquimica da parede celular durante o amadurecimento de sapoti, assim como o seu potencial de conservacao pos-colheita. Sapotis foram tratados com 1-MCP, um antagonista do etileno, a 300 nL L-1 por 12 h e, em seguida, armazenados sob atmosfera modificada a 25oC por 23 d. O 1-MCP retardou significativamente o amadurecimento de sapoti por 11 d, via diminuicao da atividade das enzimas hidroliticas da parede celular e, portanto, os frutos tratados com 1-MCP exibiram menor solubilizacao dos poliuronideos, hemicelulose e acucares neutros livres quando comparados com os frutos-controle. O 1-MCP retardou o amaciamento do sapoti, indicando que esse processo e dependente da producao e percepcao de etileno.

Produção de compensados de Pinus taeda L. E Pinus oocarpa Schiede com diferentes formulações de adesivo uréia formaldeído

The objective of this study was to evaluate the quality of both Pinus taeda and Pinus oocarpa plywood, 20 and 24-years-old, respectively, using three different formulations of urea formaldheyde resin. A total of 18 boards were produced, using three repetitions per treatment. The formulations containing a high relative proportion of the resin did not show a conclusive influence on the physical and mechanical properties of the boards. The boards made from P. oocarpa showed higher average values of the glue line strength, modulus of elasticity and modulus of rupture in comparison to boards of P. taeda. The results showed that the evaluation of the physical and mechanical properties of the board, indicate that the veneers of P. oocarpa have a high potentiality for plywood production.

Air drying of logs from an Eucalyptus urophylla clone for carbonization use

A secagem da madeira e uma das etapas do processo de carbonizacao e seu controle e de grande importância no rendimento e na qualidade do carvao vegetal produzido. Nas empresas produtoras de carvao, apos o corte, a madeira e empilhada nas margens das estradas ou proxima aos fornos de carbonizacao e e carbonizada apos 90 dias de secagem ao ar livre, quando se deseja alcancar 30% de umidade. Neste trabalho, objetivou-se avaliar a secagem ao ar livre de toras de um clone de Eucalyptus urophylla empregado na producao de carvao vegetal, analisando-se a perda de umidade no tempo, influencia da casca e do diâmetro das toras no processo. Foram utilizadas toras com casca e sem casca, com diâmetros variando de 6,0 a 21,0 cm, densidade basica media de 0,496 g/cm3 e 3,60 m de comprimento, provenientes de um talhao comercial de Eucalyptus urophylla com 8 anos de idade. Pilhas de secagem ao ar livre foram instaladas em Paraopeba, Minas Gerais, Brasil e o acompanhamento da secagem foi realizado por pesagens periodicas das toras durante 80 dias. Ao final deste estudo, observou-se que as maiores perdas de umidade ocorreram nas tres semanas iniciais. A umidade das toras sem casca (54%) e com casca (50%) foram proximas apos 80 dias de secagem, com uma maior reducao de umidade para as toras sem casca. A influencia da casca na perda de umidade foi mais pronunciada nas tres primeiras semanas. A reducao de umidade ocorreu em intensidades diferentes em funcao do diâmetro das toras. Apos 80 dias, a maior reducao de umidade foi observada nas toras sem casca: 65% para as toras de maiores diâmetros e 80% para as de menores diâmetros. Ja, para as toras com casca os resultados foram respectivamente 56% e 75%.

Predicting moisture content from basic density and diameter during air drying of Eucalyptus and corymbia logs

In air drying of Eucalyptus urophylla and Corymbia citriodora logs for the production of charcoal it is necessary to be able to predict when logs have reached the required moisture content of ≤ 35%.This study is aimed to produce models using basic density and diameter to predict the moisture content of Eucalyptus urophylla and Corymbia citriodora logs after 30, 60 and 90 days drying. 1,2 m long logs were taken at three different heights from three C. citriodora trees and three trees each from two E. urophylla clones (VM4 and Mn463). The 27 debarked, end sealed logs were air dried under cover for 90 days during which the change in moisture content was monitored. The relationship between density and drying was analyzed by Pearson’s correlation coefficient and the models for predicting the moisture content based on the basic density and diameter were produced. The density and the drying showed a high correlation coefficient. The coefficient of determination of the models was above 0,89 with a standard error lower than 6%. The use of the density and diameter to estimate the wood moisture content simplifies the production of the models, which can be used for Eucalyptus and Corymbia genetic materials.

Aproveitamento de resíduos de painéis de madeira gerados pela indústria moveleira na produção de pequenos objetos

Wood residue panels have been used in substitution of solid wood. As a consequence, the volume of residues has been increasing day-by-day. The furniture industries are the major generators of these residues. Their use as raw material for the production of handmade small objects emerges as an alternative to use the economic potential of this type of residue. The objective of this work was to produce small wood objects using boards and mixed board residues to compare their quality. At first, three workers were selected and supplied with MDF, OSB and plywood boards, as well as graphic projects of 10 small objects. Each worker produced 9 samples of each object. At a second turn, one worker was selected to produce the same 10 objects with three samples, mixing residues from three furniture industries of Uba, MG. The quality attributes of the objects were evaluated and compared. It was concluded that all the wood boards used are adequate to produce the 10 objects but some boards are better, depending on the attribute evaluated. The objects manufactured with mixed woodboard residues presented similar finishing attributes and no significant differences from the objects produced with wood boards in the following attributes: functionality, weight, proportion and symmetry. Mixing residues of different boards affected the evaluation of the attributes: finishing, beauty and color. An object made from residues of the same board can be more attractive. It is technically feasible to produce small objects using residues of wood panels generated by the furniture industry.

Gaseificação de materiais lignocelulósicos para geração de energia elétrica.

The objective of this work was to build a countercurrent gasifier in hardened mortar to evaluate the potential of generating electrical energy of eucalyptus species grown in the state of Minas Gerais, from agroindustry residues and from the mixture of those materials. The immediate chemical composition and the heat power of the materials utilized were determined. The different lignocellulosic materials were experienced, and gas was used as the control. For the factors being tested, measurements of the electric yields and consumptions of the materials were performed. The statistical design was the completely randomized with seventeen treatments and three replicates done at 5% of significance. On the basis of the results obtained and on the statistical analyses performed, it follows that the gasifier-generator set is easy to build, made with easily purchased and low cost materials. Among the materials evaluated the coal of the species, Corimbia citriodora, with 78% of fixed carbon, presented the best performance of generated power, obtaining 1,391 watts, with a constant tension of 230 volts. The residues utilized of cane bagasse, rice straw, corn cob, coffee husk and coal chaff presented no potential to generate energy by the sort of gasifier utilized.

Características do carvão de um clone de Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake

Neste trabalho, objetivou-se determinar a variabilidade existente nas caracteristicas do carvao de um clone de Eucalyptus grandis x Eucalyptus urophylla aos 6 anos, plantado no municipio de Martinho Campos, MG. As arvores foram distribuidas em tres classes de diâmetro e a amostragem consistiu na retirada de discos, de 2,5 cm de espessura, a 2%, 10%, 30% e 70% da altura comercial, alem de um a 1,30 m do solo (DAP) e, a partir deste ponto, de metro em metro ate a altura comercial. Foram tomadas amostras ao longo do raio nos discos, considerando os dois lados em relacao a medula. As amostras foram carbonizadas em forno eletrico de laboratorio, sendo determinados os rendimentos e a qualidade do carvao vegetal produzido. Pelos resultados, verificou-se que para a primeira carbonizacao, a classe diametrica influenciou significativamente o rendimento gravimetrico em carvao vegetal, em liquido pirolenhoso e o teor de cinza do carvao vegetal produzido, e que o rendimento em gas nao condensavel, o teor de materiais volateis e o de carbono fixo nao foram influenciados pela classe diametrica; para a segunda carbonizacao o rendimento gravimetrico aumentou da casca para a medula, para todas as classes diametricas e ocorreu reducao dessa caracteristica com a diminuicao das classes diametricas e que os valores de densidade relativa aparente tenderam a aumentar no sentido medula-casca, em todas as classes diametricas.

UTILIZAÇÃO DA TÉCNICA SUNSET LASER PARA DISTINGUIR SUPERFÍCIES USINADAS DE MADEIRA COM QUALIDADES SIMILARES

The ASTM D 1666-11 (2011) norm classifies the quality of wood surface pieces after its mechanical processing. Although this classification is difficult to achieve visually, the use of some tools, such as solid state laser, can facilitate this classification. The aim of this work was to evaluate the use of sunset laser to qualify mechanically processed surfaces with similar visual qualities. We used a log from the base of a Khaya ivorensis tree and one from a K. senegalensis tree, both 11 years old. 22 specimens of dimensions 600x140x30 mm (CxLxE) were made of each species. The specimens were flattened with speeds of 2400, 3600 and 4000 min-1 and advanced speeds were predetermined in 6 and 15 m.min-1. Then the samples were illuminated with sunset laser and photographed at high resolution, the images were transferred to the software Image J. To evaluate the sunset laser, areas of defects in wood that are classified as regular and bad by ASTM D 1666-11 (2011) were used. There was a difference in classification of wood defects between the two methods used, from the 31 specimens classified as regularly by visual analysis, 8 of them were classified as bad by the laser method. The use of solid-state laser in the sunset laser technique was more efficient in evaluating small differences in mechanically processed wood defects compared to visual evaluation.

Modelos de calibração e a espectroscopia no infravermelho próximo para predição das propriedades químicas e da densidade básica da madeira de Eucalyptus .

Near infrared spectroscopy (NIRS) is a fast, accurate and non-destructive method, capable of predicting wood technology properties. The aim of this study was to apply the NIRS technique for fast prediction of chemical properties and basic density of Eucalyptus wood. Clones of three-year–old Eucalyptus , from commercial plantations in Cocais, Guanhaes, Rio Doce and Santa Barbara localities in the state of Minas Gerais were used. The chemical properties and basic density of the trees were determined using traditional laboratory methods and correlated with the spectral information by Partial Least Squares Regression. The calibrations to estimate basic density showed coefficients of correlation in cross-validation (Rcv) ranging between 0.56 and 0.97 and ratio of performance to deviation (RPD) between 1.1 and 4.7. The carbohydrate, xylan and glucan contents were predicted through models with Rcv ranging from 0.39 to 0.88 and RPD from 1.1 to 2.1. For cellulose, lignin and extractive contents, the models presented Rcv between 0.10 and 0.87 and RPD values between 0.9 and 2.0. The calibration to predict S/G monomer ratio that showed the best adjustment (Rcv=0.90 and RPD=2.3) was in the trees from Rio Doce site. The near infrared spectroscopy proved to be satisfactory to provide the basic density and chemical properties of clones of Eucalyptus wood.