918 resultados para eucalyptus fiber


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O objetivo deste trabalho foi avaliar o efeito do choque térmico e mecânico na produtividade de Lentinula edodes em 140 toras de Eucalyptus saligna, completamente colonizadas pelo fungo, em diferentes tempos de imersão em água e no primeiro fluxo de produção. As toras foram imersas em água resfriada (16ºC) ou à temperatura ambiente (22ºC); os períodos de imersão corresponderam a 6, 10, 14, 18, 22, 26 e 38 horas; o choque mecânico foi acompanhado por três quedas consecutivas da tora, em posição vertical, no chão. A temperatura da água e o tempo de imersão afetaram a produção de L. edodes, resultando em aumentos significativos (2 a 4 vezes) nos tratamentos em que as toras foram submetidas à água resfriada e nos tempos de imersão mais curtos (6 e 10 horas). O choque mecânico não resultou em aumento na produção de basidiomas.

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

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A madeira roliça possui grande emprego nas construções civis, desempenhando a função de vigas, colunas, fundações, postes para distribuição de energia elétrica, entre outras, apresentando a vantagem de não ser processada, como é o caso da madeira serrada. O projeto envolvendo elementos roliços requer, além de outras variáveis estruturais, o conhecimento do módulo de elasticidade. No Brasil, os documentos normativos que tratam da determinação das propriedades de rigidez e resistência para peças roliças de madeira estão em vigência há mais de vinte anos sem revisão técnica. A madeira roliça, por geralmente possuir eixo com curvatura não nula, pode apresentar, segundo a posição da peça no ensaio de flexão, valores diferentes do módulo de elasticidade. Este trabalho tem como objetivo analisara influência da posição de peças roliças de madeira de Eucalyptus grandis na determinação do módulo de elasticidade na flexão. O ensaio de flexão utilizado é o de três pontos, sendo cada peça avaliada em duas posições distintas, definidas mediante o giro da seção transversal em torno do eixo. Os resultados encontrados indicam a necessidade do ensaio de flexão em, pelo menos, duas posições distintas da peça.

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The aim of the study was to determine the percentage of crude protein, crude fiber and crude fat (ether extract) of 25 genotypes of kale from the Germplasm Bank of Instituto Agronomico de Campinas and of one genotype grown in the region of Jaboticabal-SP. The plants were cultivated in the field, and the leaves after collection were pre-dried in a convection oven at 65 degrees C for 72 h. Afterward, the leaves were analyzed for crude protein, crude fiber and crude fat (ether-soluble materials). Significant differences were detected among the different genotypes for all the characteristics examined. of the genotypes studied, six showed more than 30% crude protein: HS-20 (32.56%), Comum (31.70%), Couve de Arthur Nogueira 2 (31.16%), Pires 2 de Campinas (30.63%), Manteiga 1-916 (30.36%), and Manteiga de Ribeirao Pires I-2446 (30.03%). In relation to crude fiber, the highest percentage was seen in the genotype Manteiga de Mococa (10.92%), differing significantly from the other genotypes studied. With regard to crude fat, the highest percentage was found in the genotype HS-20 (3.72%), and Pires 1 de Campinas (3.34%). of the genotypes tested, HS-20 stood out among the others, showing both the highest percentage of protein and fat.

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Com o objetivo de avaliar a eficiência da seleção precoce em Eucalyptus spp. foram usados dados de dois testes clonais avaliados quanto ao crescimento em altura (ALT), diâmetro à altura do peito (DAP) e volume individual de madeira (VOL) aos 25, 50 e 72 meses de idade. O delineamento experimental nos dois testes clonais foi o de blocos casualizados, com trinta tratamentos (clones), seis repetições, sendo um deles com seis e o outro com dez plantas em linha por parcela, no espaçamento de 3,0 m x 3,0 m. Foi feita a análise de variância para cada caracter e idade. Foram obtidas as estimativas de coeficiente de determinação genotípico e de correlações genotípicas entre os caracteres nas idades juvenis e na idade de rotação. Para verificar a viabilidade da aplicação da seleção precoce, foi simulada a seleção de 30% dos clones nas idades juvenis e na idade de rotação para cada um dos caracteres e idades avaliadas, obtendo-se as estimativas de ganhos genéticos com a seleção direta e indireta. Houve diferenças significativas entre os clones avaliados nos dois experimentos para todos os caracteres e idades. Com base nos resultados obtidos, é possível efetuar a seleção precoce aos 2 anos de idade sobre o caracter DAP em testes clonais de eucalipto.

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The objective of the presente study was to evaluate the effects on different dietary fiber sources and crude protein levels on the intestinal morphometry of commercial layers. Isa Brown® layers with 48 weeks of age were distributed in a completely randomized experimental design with a 3 x 2 + 1 factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. At the end of the fourth experimental period (28 days each), birds were 64 weeks of age and were randomly chosen (two birds per replicate, totaling 14 birds per treatment), weighed and sacrificed by neck dislocation. Their intestine was dissected and the duodenum, jejunum and ileum were collected for subsequent analysis of intestinal morphometry. Treatments consisted of diets containing three different fiber sources (cottonseed hulls, soybean hulls or rice husks) and two crude protein levels (12% or 16%). Soybean hulls and 16% crude protein level promoted, in general, an increase in villus height and crypt depth in the three intestinal segments. In the duodenum, the control diet resulted in higher villus height and crypt depth relative to the diets containing fiber. In the jejunum, higher crypt depth values. In the ileum, dietary fiber increased villus height as compared to the control diet.

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

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The objectives of the study were to assess changes in fine root anisotropy and specific root lengths throughout the development of Eucalyptus grandis ( W. Hill ex Maiden) plantations and to establish a predictive model of root length density (RLD) from root intercept counts on trench walls. Fine root densities (<1 mm in diameter) were studied in 6-, 12-, 22-, 28-, 54-, 68- and 72-month-old E. grandis plantations established on deep Ferralsols in southern Brazil. Fine root intercepts were counted on 3 faces of 90-198 soil cubes (1 dm(3) in volume) in each stand and fine root lengths (L) were measured inside 576 soil cubes, sampled between the depths of 10 cm and 290 cm. The number of fine root intercepts was counted on one vertical face perpendicular to the planting row (N(t)), one vertical face parallel to the planting row (N(l)) and one horizontal face (N(h)), for each soil cube sampled. An overall isotropy of fine roots was shown by paired Student's t-tests between the numbers of fine roots intersecting each face of soil cubes at most stand ages and soil depths. Specific root lengths decreased with stand age in the upper soil layers and tended to increase in deep soil layers at the end of the rotation. A linear regression established between N(t) and L for all the soil cubes sampled accounted for 36% of the variability of L. Such a regression computed for mean Nt and L values at each sampling depth and stand age explained only 55% of the variability, as a result of large differences in the relationship between L and Nt depending on stand productivity. The equation RLD=1.89*LAI*N(t), where LAI was the stand leaf area index (m(2) m(-2)) and Nt was expressed as the number of root intercepts per cm(2), made it possible to predict accurately (R(2)=0.84) and without bias the mean RLDs (cm cm(-3)) per depth in each stand, for the whole data set of 576 soil cubes sampled between 2 years of age and the end of the rotation.

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The aim of this study was to verify the average fiber length and the juvenile and mature wood zones from Hevea brasiliensis proveniences from a reforestation area in São Paulo, Brazil. For this purpose, five Hevea brasiliensis trees were randomly collected from a 50-year-old plantation, located in Balsamo, São Paulo, Brazil. The trees were cut and five flat sawn boards were obtained. The juvenile and mature wood zones were determined by fiber length measurement from the pith to the bark. The results showed that: (a) the juvenile wood of this species occurred approx. between 40 and 55 mm, from the pith, and from this point forward, the mature wood zone was found; (b) there was a significant difference between the average fiber length of juvenile wood (1.26 mm) and mature wood (1.51 mm).

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The juvenile wood presents great difference in its anatomical and physical properties in relation to the mature wood. That heterogeneity of the wood causes a series of upset for the processing industry. The present research had as objective the study of the physical properties of the juvenile and mature wood of Pinus elliottii Engelm var. elliottii, with 25 years of age and of Eucalyptus grandis Hill ex Maiden, with 30 years of age, coming from the Experimental Station of Itapetininga and State Forest of Santa Barbara, belonging to the Forest Institute of the state of São Paulo. From both species there were taken from radial boards, specimens with dimensions of 20x30x50 mm, for the determination of density, swelling and swelling coefficient of the juvenile and mature wood. The results of the species showed that the mature compared with the juvenile wood presented: (1) an increase in the values of the basic density, at 0% and at 12% of moisture content and of the volumetric, radial and tangential swelling at 12% moisture content and maximum coefficient of radial and tangential swelling; (2) a reduction in the values of longitudinal swelling at 12% and maximum and of the longitudinal swelling coefficient.

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This study aimed to evaluate the adhesion ability of eucalyptus lumber from three tillage systems, using adhesives: resorcinol formaldehyde and two adhesives in water emulsion based on vinyl poly-acetate. The management systems were characterized by three strata, the stratum one (E1) characterized by wood from coppice and 70 months of age, the stratum two (E2) characterized by wood and retirement age of 166 months and stratum three (E3), also characterized by retirement at 70 months of age. The wood was derived from a random mixture of the first two sawn logs, each three feet from the base, which comprised three treatments on the adhesive used. We evaluated the shear strength by compression tests and the percentage of wood failure in the glue line. Based on the results obtained, it can be said that the adhesion had satisfactory performance with all the resins used, and the average values of shear strength of the glue line were shown to be equivalent to the shear strength of solid wood only for the samples which adhered with 'Wonderbond' adhesive and also provide higher values for wood failure (97.64%). The highest density present in the wood of the second stratum (E2) influenced only sticking with the resorcinol formaldehyde resin. For polyvinyl acetate (Cascorez 2590), shear values decreased in the third management condition (E3).

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Este trabalho teve como objetivo avaliar os efeitos das lâminas brutas de irrigação na concentração de nutrientes de mudas de Eucalyptus grandis, produzidas em diferentes substratos. O experimento foi realizado na Camará - Mudas Florestais, em Ibaté, SP, e constituiu-se de um fatorial 5 x 4, sendo cinco lâminas brutas de irrigação diárias (6, 8, 10, 12 e 14 mm), aplicadas em diferentes horários (10, 13 e 16 h), e quatro substratos (FB - fibra de coco; CPV - casca de pinus e vermiculita; CATV - casca de pinus, carvão, turfa e vermiculita; e um MIX - 70 % de CPV e 30 % de FB). Foram determinadas os conteúdos dos nutrientes na parte aérea e no sistema radicular das mudas. Os resultados indicaram que houve influência das lâminas de irrigação e dos substratos no conteúdo dos nutrientes das mudas com maior acúmulo dos mesmos à medida que o fornecimento de água foi maior. As plantas crescidas nos substratos FB e CPV registraram os maiores acúmulos de nutrientes. CPV foi o melhor em se tratando do acúmulo dos macronutrientes nas raízes e também, juntamente com FB, o melhor para o acúmulo dos micronutrientes nas raízes e na parte aérea. Não houve influência dos substratos no acúmulo dos macronutrientes na parte aérea, porém houve das lâminas de irrigação.

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This paper mainly aimed to evaluate the physical and mechanical properties of LVL panels made from Eucalyptus grandis, from reforestation at the region of Senges, in Parana state, Brazil. LVL panels were manufactured using 23 veneers (2,4mm thick each one) in commercial dimension of 2.500 mm long and 1,200 mm wide. The properties of static bending were analyzed (strength and rigidity) in beams of the LVL, in the flatwise and edgewise positions. The properties of compression parallel to grain and shear parallel in the plans L-X and L-Y and density in this LVL panels were also analyzed according to ASTM-D 5456/4761 and ASTM-D 198 codes. The mean values to flatwise bending MOE and MOR were 13114 MPa and 88.76 MPa, respectively, and for edgewise bending MOE and MOR were 15871 MPa and 88.63 MPa, respectively. The density (12%) of the LVL panels and of the veneers were 690 kg/m(3) and 649 kg/m(3). The mean values to parallel compression MOE and MOR were 16856 MPa and 58.05 MPa, respectively. The mean values of the maximum resistance to shear parallel in the plans L-X and L-Y were 5.96 MPa and 591 MPa, respectively. All these values reached partially or they passed the medium limits of reference (normative codes, researches and commercial catalogs) established for LVL panels and original solid wood, attesting overall the quality of those panels produced with this wood.

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This work evaluated the viability of one commercial substrate with pinus bark, vermiculite and 30% of coconut fiber for Eucalyptus grandis seedlings production under different water management: 6, 8, 10, 12 e 14 mm day(-1). In relation to the substrates, it was evaluated, before and after the seedlings production, the total content of carbon, nitrogen and organic substances, pH and EC of the extract, the content of macronutrients (P, K, Ca, S, Mg) and macronutrients (B, Fe, Mn, Cu, Zn), as well as total porosity, density and water retention. It was evaluated the macro and mcronutrients accumulation in the roots and in the aerial part of the seedlings, 105 days after sowing. It was concluded that the substrates presented some distinct properties of those cited as ideal for production in containers with irrigation and fertilization. At the end of the production process, both substrates registered nutrient content little influenced by water management what would guarantee the initial development of the plants in the field.