Influência do cancro basal em Eucalyptus grandis nas propriedades da madeira e polpação kraft

The objective of this research is to assess the influences of basal canker on wood properties for the kraft pulp production. The material consisted of seeded E. grandis trees classified into 4 levels of basal canker severity (0, 1, 2 and 3) and installed in three soil types classified by texture (AQ1 and AQ2 - 10 to 15% clay, and LEm2 - 26 to 35 clay). The sampling consisted of randomly selecting five trees for each for each canker severity level and soil type, totaling 60 trees (4 canker levels x 3 soil types x 5 trees). These trees were fallen and cut into sections at 0, 25, 50, 75 and 100% of the commercial height for the collection of disk and logs of wood. The results showed that the soil texture influences in the Eucalyptus canker severity and this fact should be considered when assessing the wood properties and their final destination. The texture of the soil and the severe levels of basal canker influence the wood properties, and therefore the kraft pulping.

Análise das propriedades da madeira de estrutura de telhado após a ocorrência de um incêndio

The present study evaluated the mechanical properties of pieces of wood coming from the roof structure of a residence subject fire in the rural area of Itapeva/SP. The structure was built 25 years ago using wooden beams of the species Guarucaia (Peltophorum vogelianum), where the specimens were removed. The research methodology included qualitative evaluation of the samples, estimating the layer pyrolysis and carbonization of the wood, measuring of density and mechanical tests of compression parallel to grain, tension parallel to grain and shear. The mechanical properties of wood were analytically correlated with the layers carbonization and pyrolysis that are influenced by the temperature and time of fire; these values were estimated at 1000 °C and two hours for the case in question. The results indicate that the strength properties of degraded wood are different from a healthy wood. The level of thermodegradation, in general, can be measured by density, result in weight loss due to decomposition of the wooden components.

Efeito da termorretificação nas propriedades físicas, mecânicas e na resistência a fungos deterioradores da madeira de Eucalyptus grandis Hill ex Maiden

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Degradação da madeira por caruncho em edifícios antigos: uma análise experimental

O presente trabalho apresenta um estudo laboratorial que teve como finalidade o reconhecimento de perda de propriedades da madeira de edifícios antigos quando degradada por carunchos. Foi estudada madeira antiga de pinho e de choupo, com idades compreendidas entre 100 e 200 anos. Como abordagem inicial são apresentadas as características da madeira e dos edifícios pombalinos e gaioleiros onde esta era bastante usada, não só como elemento deacabamento, mas principalmente como elemento estrutural. São apresentados os vários fatores que levam à degradação da madeira assim como alguns métodos de avaliação e diagnóstico dos estados de conservação dos elementos de madeira que se encontram nos edifícios. É também desenvolvido um estudo sobre o caruncho grande e caruncho pequeno, seu ciclo de vida e forma como degrada a madeira, servindo de base ao estudo laboratorial. No desenvolvimento foi avaliado o estado de degradação de provetes de madeira antiga com 30 x 30 x 90 mm e de seguida correlacionado com a sua resistência à compressão, o seu módulo de elasticidade e a extensão em fase plástica. Desta forma pretende-se estudar o modo como os diferentes estados de degradação por caruncho influenciam as caraterísticas mecânicas das peças de madeira.

Análise energética da madeira e do carvão de híbridos entre Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson e Corymbia torelliana (F. Muell.) K.D. Hill & L.A.S. Johnson

This research aimed to evaluate the wood and charcoal quality of hybrids clone of the crossing C. citriodora with C. torelliana in two different locations for charcoal production. Seven with 3,75 years old clones, planted at country of Itamarandiba – MG, and six 6,42 years old clones, planted in Dionísio – MG, were studied. For wood and charcoal quality analysis, samples were collected along the stem of the trees until the commercial height. Properties study of the wood was done by chemical analysis, basic density, superior heat power, and thermogravimetric analysis. The wood samples were carbonized in laboratory conditions with heating rate of 1.67 0 C.min -1 , starting at 100 0 C until 450 0 C and keeping on this temperature for 30 minutes. It were determined the carbonizations gravimetric yield, all in dry basis. The wood quality was evaluated based on the chemical immediate analysis, relative apparent density, and gross heating value. The experiment was installed according to the completely randomized design, with five repetitions. The collected data were submitted to analysis of variance and, when the evaluated effects were significant by “F” test, was applied the Scott-Knott test at 5% probability for multiple comparisons. For correlation analysis, Pearson correlation coefficient, tested by the "t" test at 5% probability was used. Results showed variability of wood between the genetic materials evaluated in relation to place and plant crossing. The thermal analysis of the wood showed significant variation between clones and it was possible to differentiate two stages of degradation (hemicelluloses and cellulose). The majority of the clones presented satisfactory properties for the charcoal production, while, clone 3, planted in Itamarandiba, obtained the best performance due it have the higher yield and energetic efficiency, thus, achieving the best potential for charcoal production. However, clone 9, planted in Dionísio, was the less indicated for charcoal production since it presented the lowest energetic efficiency, gravimetric yield, and densities.

Estudo comparativo da madeira e polpação de Eucalyptus urophylla e do híbrido E. urophylla x E. grandis em dois modelos silviculturais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação da densidade da madeira de clones de Eucalyptus spp. a idades passadas com uso da técnica de atenuação de radiação gama

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização físico-mecânica de elementos estruturais roliços perfilados de Amaru

The study of physical and mechanical properties of wood is essential for its structural use and it is of great importance to the construction industry. Thus, this study aimed to determine the physical and mechanical properties of the wood Amaru - a hybrid of Eucalyptus, developed by Plantar Projects and Forest Products Ltda. In order to determine the properties of Amaru, round samples were used, which were provided to the Laboratory of Wood and Wooden Structures of the School of Engineering of São Carlos, University of São Paulo - LaMEM / EESC / USP. For the characterization of the physical properties, the apparent specific gravity and moisture content of the samples were determined. To the mechanical characterization, the following properties were evaluated: strength and stiffness in compression, strength and stiffness in bending, shear and tension. The procedures of the tests performed in this study were done according to the recommendations of the Brazilian Wood Standard ABNT NBR 7190:1997. The specimen used were confectioned in actual dimensions, according to as those used in the construction system proposed by Plantar. The results obtained from the tests performed showed that the mechanical properties approached the values proposed by the Wood Standard NBR 7190. The visual grading was important to provide a primary idea about the failure modes to be obtained from the tests performed. The bending test showed the modulus of elasticity (MOE) and Modulus of Rupture (MOR), which resulted in 15822 MPa and 101,7 MPa, respectively. The compression test resulted in values Ec0,m and fc0, 15698 MPa and 50,7 MPa. The tensile strength (ft0) of this hybrid was calculated and its value obtained was 60,8 MPa. The shear strength (fv0) was 8,2 MPa. The results obtained from the tests are the basis for engineers and architects to design structures using wood species Amaru

Avaliação dos aspectos de processo no torneamento de madeiras tratadas termicamente

Pós-graduação em Engenharia Mecânica - FEG

Quality of wood and pulp from a clone of Eucalyptus grandis planted at three locations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Propriedades de resistência e rigidez da madeira juvenil e adulta de Pinus taeda L.

O objetivo do presente trabalho foi o estudo da variabilidade das propriedades de resistência e rigidez à flexão estática e à densidade aparente (12%) entre a madeira juvenil e adulta de Pinus taeda L., de 37 anos de idade, procedente do Horto Florestal de Manduri, Estado de São Paulo. Na primeira parte do trabalho foram determinadas a região de madeira juvenil, a região de transição e a região de madeira adulta, por meio de estudos anatômicos (comprimento dos traqueídes axiais), segundo as recomendações das normas ABNT e IAWA. Os resultados mostraram que a região de madeira juvenil dessa espécie ocorre aproximadamente até o 18º anel de crescimento. Na segunda parte do trabalho foram analisados a resistência (módulo de ruptura - MOR) à flexão, o módulo de elasticidade (MOE) nessa mesma solicitação e a densidade aparente (12%) para as madeiras juvenil e adulta. Os resultados mostraram que o MOE e o MOR da madeira juvenil foram menores e mais variáveis que aqueles obtidos para madeira adulta. A densidade apresentou a mesma tendência observada nas propriedades avaliadas no ensaio de flexão estática.

Propriedades de contração na madeira juvenil e adulta de Pinus taeda L.

This paper had the objective of studying variability of radial, tangential, longitudinal and volumetric shrinkage between the juvenile and mature wood, from a 35 year-old Pinus taeda L., from Horto Florestal of Manduri at São Paulo State, Brazil. First of all the experimental program determinations were related to the juvenile wood, region of the transition and region of the mature wood, using anatomical analysis (length of the axial tracheids), according to ABNT and IAWA codes. Results had shown that the area of juvenile wood of this species occurs approximately until the 20th growth ring, being more representative until the 12th ring. The transition area of this wood occurs between the 12th and 20th growth ring. In the second part of the work the shrinkage of the juvenile and mature wood were evaluated. Values of the radial, tangential and volumetric shrinkage were smaller and more variable on the juvenile wood. The longitudinal shrinkage did not present significant differences between the two wood types; medium values were slightly inferior and very variable on juvenile wood related to mature wood.

Determinação das propriedades físicas e químicas da madeira de Hevea brasiliensis em relação ao painel de extração de látex

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da vaporização na madeira de Eucalyptus grandis sobre as suas propriedades químicas e resistência natural a fungos e cupins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação das propriedades físico-mecânicas da madeira de árvores de Hevea Brasiliensis em três condições de sanidade no Estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)