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Propriedades de resistência e rigidez da madeira juvenil e adulta de Pinus taeda L.
Ballarin, Adriano Wagner;Palma, Hernando Alfonso Lara;
Revista árvore , 2003, DOI: 10.1590/S0100-67622003000300014
Abstract: this paper aimed to study the variability on rigidity (moe) and strength (mor) properties in static bending and density (12 %) between juvenile and mature wood of 37-year-old pinus taeda l. trees from horto florestal, manduri, sao paulo, brazil. in the first part of the experimental program, the juvenile, transition and mature wood zones were determined using anatomical analysis (tracheids length) according to the abnt and iawa codes. results showed that juvenile wood zone occurs approximately up to the 18th growth ring. in the second part of the experimental setup, bending tests were performed with both juvenile and mature wood samples gathered in two distinct groups to obtain their modulus of rupture - mor, modulus of elasticity -moe and density (12%). results showed that moe and mor of juvenile wood were always smaller and presented more variability, when compared to mature wood. density at 12% showed the same tendency observed in the mechanical tests.
Determina??o do módulo de elasticidade da madeira juvenil e adulta de Pinus taeda por ultra-som
Ballarin, Adriano W.;Nogueira, Marcelo;
Engenharia Agrícola , 2005, DOI: 10.1590/S0100-69162005000100003
Abstract: pinus sp. wood has an increasing importance on supplying brazilian wood industry. the diminution of adult and large diameter trees supply deriving from natural tropical forests, became usual the production of wood on short rotation plantation, with considerable proportion of juvenil wood. results from several researches have been demonstrated that moe and mechanical strength are strongly affected by juvenile wood occurrence. this research was developed with the main objective of correlating dynamic modulus of elasticity (non-destructive ultrasound tests) and moe. six trees of pinus taeda, 34 years old from the controlled plantations of the esta??o experimental de itapeva - sp, brazil, were randomly chosen for the experimental program. each tree resulted on four logs (3.75 m long), and from each log the central board was used (80 mm thick). boards were dried to 12% moisture content and from them longitudinal specimens (4 cm x 4 cm x 45 cm) were sawed. all specimens were submitted to non-destructive tests (ultrasonic method) and destructive conventional compression tests. results had shown good sensitivity of the method of the ultrasound (r2 ? 0,90) on evaluating moe of juvenile and mature wood.
Setsuo Iwakiri,Claudio S. Del Menezzi,Christine Laroca,Ivan Venson
CERNE , 2002,
Abstract: The objective of this study was to evaluate the quality of the plywood, manufactured from Pinus taeda and Pinus oocarpa, with 20 and 24 years old respectively, using three differentformulations of the fenol-formaldheyde resin. The results of the glue line shearing tests not showed statistical differences between the species and three resin formulations. In the hot water test, all of the boards were classified as “BR” and, the boards of the Pinus oocarpa produced with formulations (1)and (3), were classified as “WBP”. The different resin formulations not influenced on the modulus ofelasticity (MOE) and modulus of rupture (MOR) The boards of Pinus taeda with formulations (1) and(2) showed higher values of MOE in comparison of the Pinus oocarpa. The MOR of the Pinus oocarpa withformulation (2) was higher than Pinus taeda. The mechanical properties of the plywood wereprobably influenced by wood variability related to sapwood and hartwood, thickness of growth ringsand, springwood and summerwood.
Effect of Climate Variables on Monthly Growth in Modeling Biological Yield of Araucaria angustifolia and Pinus taeda in the Juvenile Phase  [PDF]
Naiara Teodoro Zamin,Sebasti?o do Amaral Machado,Afonso Figueiredo Filho,Henrique Soares Koehler
International Journal of Forestry Research , 2013, DOI: 10.1155/2013/646759
Abstract: The aim of this study was to investigate the effect of climate variables on monthly growth in diameter and height of Araucaria angustifolia (Bert.) O. Kuntze and of Pinus taeda L., over a six-year period, as well as verifing the contribution of these variables in the composition of the Chapman-Richards model. To this end, we selected 30 trees of each species and measured monthly the diameter and height, between June 2006 and August 2012. The climate variables were obtained from two SIMEPAR meteorological stations near the plantings. A correlation matrix was constructed to determine the effect of climate variables on the monthly growth. Next a principal component analysis (PCA) was conducted to determine the climate variables to be included in the fit of the Chapman-Richards model. The results indicated that the climate variables with the highest correlation (about 0.6) with monthly growth in diameter and height of the species were temperature, photoperiod and atmospheric pressure, and precipitation for some years of the study. The fitted model that included climate variables showed reduced Syx% of about 0.8% compared to the traditional biological model. However, ANOVA showed no statistical difference between the production estimates obtained by both models. 1. Introduction In forestry planning knowledge of the present and future growth and yield of trees and forest stands is important as it aids in the implementation of appropriate management regimes, when the quality of the final product is the goal for an increasingly demanding consumer timber market. In this context, biological modeling becomes a useful tool in planning forest production. Moreover, Maestri [1] pointed out that modeling growth is possible only if a perfect match between the measurements of stands in forest inventory and environmental variables is carefully aligned in spatial and temporal terms. However, environmental characteristics are not reflected in traditional biological growth models, which only consider tree growth as a function of the size and age of the individuals. In this sense, statistical methodologies have evolved in recent years, enabling a breakthrough in forest data modeling, and thereby allowing researchers to arrive at estimates that represent reality with increasing accuracy, a fact that has motivated numerous attempts to model the environmental factors in association with biological growth and yield. This fact suggests that establishing a link using modeling between environmental variables and the productive capacity of the forest stand seems to contribute to the
MECANIC PROPERTIES EVALUATION OF PLYWOOD PANELS OF Eucalyptus dunnii AND Eucalyptus dunnii/Pinus taeda
Peterson Jaeger,Marcelo Ziger
CERNE , 2007,
Abstract: The use of eucalyptus has been spreading out in Brazil and in several wood processing sectors. Apprehension relatedto lack of raw material in the south of Brazil makes eucalyptus an alternative for the substitution or use together with pine for makingplywood panels. Thus, the aim of this paper was to evaluate the mechanical properties of two types of plywood panels: one that isproduced with alternate plates of Eucalyptus dunnii and Pinus taeda (T1) and the other entirely with E. dunnii (T2). The results showedthat the elasticity module (MOE) in T1 was inferior to T2, but with variance presenting higher value, indicating smaller stability of thetested material. This behavior was noticed in cutting directions, perpendicular and parallel. The module of rupture (MOR) showedsimilar values in both directions of cutting, but T1 showed higher variances only in the transversal direction. The resistance to cuttingin the glue line in the treatment with cool water was similar in both treatments, with T2 presenting higher variance. On the same test16% of the pieces of T1 came off during pre-treatment. When put to boil, T2 obtained better results, even though it presented a higherpercentage of pieces coming off during pre-treatment.
Damage caused by different levels of artificial defoliation, simulating the leaf-cutting ants attack on young plantations of Pinus taeda and Eucalyptus grandis Danos causados por diferentes níveis de desfolha artificial para simula o do ataque de formigas cortadeiras em Pinus taeda e Eucalyptus grandis
Wilson Reis Filho,Franciele dos Santos,Priscila Strapasson,Mariane Aparecida Nickele
Pesquisa Florestal Brasileira , 2011, DOI: 10.4336/2012.pfb.65.37
Abstract: The artificial defoliation allows to measure the defoliation intensity caused by insects. The objectives of this work were to evaluate the damages caused by leaf-cutting ants in young plantations of Pinus taeda and Eucalyptus grandis using different levels of artificial defoliation. A classification was established according to defoliation levels that were caused by leaf-cutting ants in P. taeda: level 1: 50%, level 2: 75%, level 3: 100% and level 4: 100%, including the cut of the apical meristem. And in E. grandis: level 1: 50% of defoliation; level 2: 75% and level 3: 100%. After one year, the P. taeda seedlings had losses in diameter and height for defoliation level above 75%. Seedlings severely defoliated (level 4), had losses of 37.0% in height and 45.4% in diameter. The E. grandis seedlings had losses since three months old and the reductions were proportional to the defoliation intensity. After one year, the losses of 13.3% in height and 20% in diameter were verified in plants with 100% of defoliation. P. taeda plants are more damaged by leaf-cutting attack. doi: 10.4336/2011.pfb.31.65.37 A desfolha artificial permite mensurar a intensidade do dano devido à desfolha causada por insetos. No presente estudo, buscou-se avaliar os danos causados por formigas cortadeiras em plantios de Pinus taeda e Eucalyptus grandis com 30 dias de idade. Foi estabelecida uma classifica o baseada em níveis de desfolha semelhantes aos causados por formigas cortadeiras. Para P. taeda, os níveis foram: N1: 50%, N2: 75%, N3: 100% e N4: 100% de desfolha, incluindo o corte do meristema apical. Para E. grandis, os níveis foram N1: 50%, N2: 75% e N3: 100% de desfolha, incluindo o corte do meristema apical. Após um ano, as mudas de P. taeda tiveram perdas em altura e diametro nos níveis de N2 a N4. Mudas de P. taeda desfolhadas no nível N4 apresentaram perdas de 37,0% em altura e 45,4% em diametro. As mudas de E. grandis apresentaram perdas aos três meses de idade, sendo estas proporcionais à intensidade de desfolha. Após um ano, verificaram-se perdas de 13,3% em altura e 20% em diametro, nas plantas de P. taeda que tiveram 100% de desfolha. Plantas de P. taeda foram mais prejudicadas pela simula o do ataque de formigas cortadeiras do que as de E. grandis.
Modelo para prognose do crescimento e da produ??o e análise econ?mica de regimes de manejo para Pinus taeda L.
Acerbi Jr., Fausto Weimar;Scolforo, José Roberto Soares;Oliveira, Ant?nio Donizette de;Maestri, Romualdo;
Revista árvore , 2002, DOI: 10.1590/S0100-67622002000600007
Abstract: this study aimed to develop a prognosis system for growth and yield of pinus taeda l. to simulate and evaluate several management regimes for the production of multiple use clearwood to analyze the economic feasibility for several sites, spacings, and wood discount rates and prices, based on owned and rented land plantations. the developed model was based on the compatibility of stand basal area model and diametric class model. the weibull distribution was chosen to allow the prognosis for several strata and stand ages. a thinning simulator is then applied to obtain the desired remaining stand. a new prognosis is then made and a new thinning simulation applied. this procedure is repeated up to pinus sp. the final cutting, using the sppinus (prognosis yield system for pinus sp.). for the economic analysis, two scenarios were compared, using various numbers, periods and thinning intensities, based on different initial planting intensities and various yield levels. a sensitivity analysis of the economic performance was conducted for each management regime, considering three discount rate levels, two wood price levels and the option of owing or renting land. it was concluded that: the model proposed did not present bias in volume and growth estimates; the management regime with a pre-commercial followed by two commercial thinnings should be adopted; renting land for pinus sp. plantation is economically feasible but owing land is more profitable; the initial spacing should be of 833 trees/ha; and pruning improves wood quality that increases wood price, that will eventually enhance the economic feasibility of management regimes.
Effect of technological parameters and wood properties on cutting power in plane milling of juvenile poplar wood  [cached]
Barcík ?tefan,Pivolusková Eva,Kminiak Richard
Drvna Industrija , 2008,
Abstract: This paper presents the results of experimental measurements aimed at observing the effect of technological parameters (cutting speed vc and feed speed vf ), type of wood (juvenile wood and mature wood) andwood species (aspen Populus tremula, L. and hybrid poplar Populus x Euramericana Serotina“) on cutting power during plane milling of poplar wood. The results showed the reduction of cutting power with the decrease of cutting speed and feed speed. Lower cutting power was also measured in milling hybrid poplar than in milling aspen. The test also confirmed the effect of different anatomical and chemical structure of juvenile wood in relation to mature wood on different physical and mechanical properties of such wood and hence also on the cutting power in processing juvenile wood.
Hygroscopicity of wood from Eucalyptus grandis and Pinus taeda subjected to thermal treatment
Modes, Karina Soares;Santini, Elio José;Vivian, Magnos Alan;
CERNE , 2013, DOI: 10.1590/S0104-77602013000100003
Abstract: this study aimed to investigate the effect of the thermal treatment technique under two conditions-autoclave combined with electric oven and electric oven only-on the hygroscopic properties of wood from pinus taeda l. and eucalyptus grandis w. hill ex maiden, comparing them with results obtained for untreated wood. three trees at age 25 years were sampled, with boards being removed at dbh level in order to make specimens 2.5 x 2.5 x 5.0 cm in size in the radial, tangential and axial direction respectively. in the combined treatment, specimens were subjected to thermal treatment in an autoclave set at 130°c/± 3°c and kgf/cm2 pressure for 3 hours, then to a conditioning period, followed by heat in an electric oven set at 160°c/±1°c for the same time. properties being evaluated included water absorption rate, volumetric swelling, water repellency effectiveness and anti-swelling efficiency. results revealed that the thermal treatments being adopted were effective in reducing hygroscopicity and in increasing the dimensional stability of both species, revealing also that the combined autoclave and electric oven treatment provides best results.
Dendronutrition as a tool to evaluate Pinus taeda wood productivity and quality Dendronutri o como ferramenta para avalia o da produtividade e da qualidade da madeira de Pinus taeda
Antonio Francisco Jurado Bellote,Mario Tomazello Filho,Renato Antonio Dedecek
Pesquisa Florestal Brasileira , 2010, DOI: 10.4336/2012.pfb.54.85
Abstract: The objective of this work was to evaluate the effect of mineral nutrients on tree growth and wood quality of Pinus taeda, on commercial plantation at 20 years after planting, on different soil types. Experimental plots were set, and from trees representing each population, stem disks were collected at different heights. Tree growth, wood quality and growth ring parameters – tracheids diameter and radial density by X-ray densitometry – were analyzed and related to mineral nutrient contents. Results showed negative correlation among Mn and Mg stem disk contents and Pinus taeda tree growth; negative correlation was also obtained among Ca, Mg and Mn contents and tracheids dimensions and wood density. There was no correlation among N, P, K and B contents in stem disks and tree growth or wood quality studied variables. Dendronutrition concept – study of relationship among tree growth parameters and growth rings to mineral nutrient contents in stem – is discussed in this work. Com o objetivo de avaliar o efeito dos nutrientes minerais na produtividade e qualidade da madeira de Pinus taeda, em planta es florestais com 20 anos, em diferentes tipos de solo. Foram demarcadas parcelas experimentais e selecionadas árvores representativas da popula o para coleta de discos do lenho, a diferentes alturas do tronco. Parametros de crescimento das árvores e de qualidade da madeira e dos anéis de crescimento - dimens es dos traqueídeos e densidade radial por densitometria de raios X - foram analisados e relacionados com o teor de nutrientes minerais. Os resultados mostraram correla es negativas entre o teor de Mn e Mg no lenho com o crescimento das árvores e entre os teores de Ca, Mg e o Mn e as dimens es dos traqueídeos e densidade do lenho; n o foi verificada correla o entre os teores de N, P, K e B no lenho com as variáveis analisadas. O conceito de dendronutri o - estudo da rela o entre os parametros de crescimento das árvores e dos anéis de crescimento com os nutrientes minerais no lenho - é discutido no presente trabalho.
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