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Search Results: 1 - 10 of 41246 matches for " Paulo Fernando Trugilho "
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Densidade básica e estimativa de massa seca e de lignina na madeira em espécies de Eucalyptus
Trugilho, Paulo Fernando;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000500005
Abstract: the objective of the research was to use three different forms to calcuate the basic wood density of trees to obtain the estimate of dry mass and lignin mass of nine eucalyptus wood species, at different ages. three different forms were used to estimate the basic density of wood, at only one point on the trunk (1,3 m of height from the ground), the average weighted estimate by volume, and the arithmetical average. these estimates were used for the determination in the estimates of dry mass and lignin mass in the wood. the results showed the eucalyptus grandis w. hill., at four years of age, and the hybrid, at other ages were the species that highlighted in volumetric increment. the effects of species, age, and interaction species x age were significant for all the evaluated features. the effect of the estimate form was only significant for the basic density at ages five, six, and seven years. the hybrid was the only species that presented a difference in the forms of estimating basic wood density. eucalyptus grandis and the hybrid were the species that highlighted in the production of dry mass and lignin, in spite of not being wood with the greater basic density and lignin content. the volumetric increment played an important role in the estimates of dry mass and lignin in the wood. so, it must be considered in all applications of wood that depend on these estimates.
Dimas Agostinho da Silva,Paulo Fernando Trugilho
CERNE , 2003,
Abstract: The objective of this work was to verify the dimensional behavior of heartwood woodand sapwood submitted to different temperatures. It was evaluated volumetric, sectional and lineardimension reduction in heartwood and sapwood of Hymeneae courbaril L submitted to finaltemperatures of 200o, 300o, 400o, 500o, 600o, 700o, 800o and 900°C, in an electric kiln with mediumrate of heating of 1.3oC/minute. For the measurement of the dimensions, accomplished before andafter the thermal treatments, an image analyzer (Midro-Videomat Zeiss) was used. It was obtained,with base in the individual readings accomplished in the image analyzer, the rates of longitudinal andtraverse linear, longitudinal and traverse sectional and volumetric reduction. The results showed thattem- perature increase of 1000C, average reduction rate reached 2.55% and 4.24%, 5.95% and 7.21% and 8.36% in the longitudinal and traverse linear dimensions, longitudinal and traverse sectional andvolumetric, respectively, for heartwood. For sapwood the values were, respectively, 2.64% and 5.02%,6.70% and 8.17% and 9.15%. For both sapwood and heartwood the largest reduction rates occurredin temperatures between 300o and 5000C. The heartwood presented larger resistance to the action ofthe temperature, however its thermal decomposition was more pronounced than that of sapwood inthe temperature range of 200-300 0C. This behavior is similar to that of lignin in relation to cellulose.
Relationships and estimates of longitudinal growth stress in Eucalyptus dunnii at different ages
Trugilho, Paulo Fernando;Oliveira, José Tarcísio da Silva;
Revista árvore , 2008, DOI: 10.1590/S0100-67622008000400014
Abstract: the objective of this study was to obtain estimates of longitudinal growth stresses in standing trees of the eucalyptus dunnii maiden at eight, thirteen, fifteen and nineteen years of age and to determine their relationships with wood characteristics. the longitudinal growth stresses were indirectly measured by the "cirad-forêt" method and estimated from both the dynamic modulus of elasticity and the modulus of elasticity in tension parallel to the grain. the longitudinal residual strain (lrs) and the estimates of the longitudinal growth stresses tended to increase with the age of the material. the lrs correlated positively and significantly with all the growth stresses estimates. the largestes magnitudes were at 13, 15 and 19 years of age. the basic density presented high, positive and significant correlations with the dynamic modulus of elasticity, estimated in the longitudinal direction, for wood saturated and at 12% moisture content, for all the ages assessed. all the growth stresses estimates presented high, positive and significant correlations between themselves.
Thiago Campos Monteiro,Jos?? Tarc?-sio Lima,Paulo Fernando Trugilho
Revista Ciência da Madeira , 2012,
Abstract: O objetivo deste trabalho foi avaliar a energia armazenada nos diferentes res -duos do desdobro das toras de Eucalyptus grandis. Foram utilizadas dez toras de Eucalyptus grandis provenientes de um plantio com 15 anos de idade, retiradas de uma rea da Universidade Federal de Lavras. As toras foram serradas em uma serra de fita simples e em seguida os pranch μes foram resserrados em uma serra circular. Os res -duos gerados foram classificados como costaneiras, aparas, serragem e casca. A energia armazenada nos res -duos foi determinada atrav s do poder calor -fico superior (PCS) e em seguida convertida em kWh. O volume de res -duos gerado representou 56% do volume das toras. A energia armazenada no composto de costaneiras e aparas e na serragem n £o diferiram estatisticamente e apresentaram PCS igual a 4735 kcal.kg-1. A energia armazenada na casca foi estatisticamente inferior e apresentou PCS igual a 3833 kcal.kg-1. The aim of this experiment was to evaluate the energy stored in the various wastes of the sawing of Eucalyptus grandis logs. Ten logs of Eucalyptus grandis were used. The logs were cut from 15-year-old trees, taken from an area of the Federal University of Lavras. The logs were sawed with a simple band saw and then the planks were re-sawed with a circular saw. The waste has been classified as slabs, shavings, sawdust and bark. The energy stored in the waste was determined by superior calorific value (SCV) and then converted into kWh. The volume of waste generated represented 56% of the volume of logs. The energy stored in a composite of slabs and shavings and in the sawdust were not statistically different and showed a SCV of 4,735 kcal.kg-1. The energy stored in the bark was significantly statistically lower and showed a SCV of 3833 kcal.kg-1.
Paulo Fernando Trugilho,José Tarcisio Lima,Fábio Akira Mori
CERNE , 2003,
Abstract: The analysis of canonical correlation measures the existence and the intensity of the association between two groups of variables. The research objectified to evaluate thecanonical correlation between chemical and physical characteristics and fiber dimensional ofwood of Eucalyptus grandis and Eucalyptus saligna clones, verifying the interdependenceamong the groups of studied variables. The analysis indicated that the canonical correlationswere high and that in two cases the first and second pair were significant at the level of 1% ofprobability. The analysis of canonical correlation showed that the groups are notindependent. The intergroup associations indicated that the wood of high insoluble lignin contentand low ash content is associated with the high radial and tangential contraction and highbasic density wood.
Márcio Pereira da Rocha,Paulo Fernando Trugilho
CERNE , 2006,
Abstract: This research evaluated the quality of Eucalyptus dunnii sawn wood for use in the lumber industry. Logs of 25 and 30 cm of diameter were used, broken down according to two methods. The first method produced boards with tangential faces and the other method produced boards with radial faces. Defects such as crooking, bowling, cupping, and index of cracks in boards, in two humidity conditions, were appraised. Defects were appraised before and after drying, i.e. after reaching the humidity balance. The crooking was more intense in radial boards. The bowling was similar in the two studied systems. Cupping only happened in tangential boards after drying. Cracks were more intense in tangential break down, presenting larger evolution after drying, when compared with radial break down. The breaking down system envisaging boards with radial faces presented pieces of better conditions for industrial purposes.
Predicting the morphological characteristics and basic density of Eucalyptus wood using the NIRS technique
Lívia Cássia Viana,Paulo Fernando Trugilho,Paulo Ricardo Gherardi Hein,José Tarcísio Lima
CERNE , 2009,
Abstract: This work aimed to apply the near infrared spectroscopy technique (NIRS) for fast prediction of basic density and morphological characteristics of wood fibers in Eucalyptus clones. Six Eucalyptus clones aged three years were used, obtained from plantations in Cocais, Guanh es, Rio Doce and Santa Bárbara, in Minas Gerais state. The morphological characteristics of the fibers and basic density of the wood were determined by conventional methods and correlated with near infrared spectra using partial least square regression (PLS regression). Best calibration correlations were obtained in basic density prediction, with values 0.95 for correlation coefficient of cross validation (Rcv) and 3.4 for ratio performance deviation (RPD), in clone 57. Fiber length can be predicted by models with Rcv ranging from 0.61 to 0.89 and standard error (SECV) ranging from 0.037 to 0.079 mm. The prediction model for wood fiber width presented higher Rcv (0.82) and RPD (1.9) values in clone 1046. Best fits to estimate lumen diameter and fiber wall thickness were obtained with information from clone 1046. In some clones, the NIRS technique proved efficient to predict the anatomical properties and basic density of wood in Eucalyptus clones.
Near infrared spectroscopy for estimating wood basic density in Eucalyptus urophylla and Eucalyptus grandis
Paulo Ricardo Gherardi Hein,Ana Carolina Maioli Campos,Paulo Fernando Trugilho,José Tarcísio Lima
CERNE , 2009,
Abstract: Wood basic density is indicative of several other wood properties and is considered as a key feature for many industrialapplications. Near infrared spectroscopy (NIRS) is a fast, efficient technique that is capable of estimating that property. However,it should be improved in order to complement the often time-consuming and costly conventional method. Research on woodtechnological properties using near infrared spectroscopy has shown promising results. Thus the aim of this study was to evaluatethe efficiency of near infrared spectroscopy for estimating wood basic density in both Eucalyptus urophylla and Eucalyptus grandis.The coefficients of determination of the predictive models for cross validation ranged between 0.74 and 0.86 and the ratio performanceof deviation (RPD) ranged between 1.9 and 2.7. The application of spectral filter, detection and removal of outlier samples, andselection of variables (wavelength) improved the adjustment of calibrations, thereby reducing the standard error of calibration (SEC)and cross validation (SECV) as well as increasing the coefficient of determination (R2) and the RPD value. The technique of nearinfrared spectroscopy can therefore, be used for predicting wood basic density in Eucalyptus urophylla and Eucalyptus grandis.
Utiliza??o de eucaliptos e de madeiras nativas no armazenamento da aguardente de cana-de-a?úcar
Mori, Fábio Akira;Mendes, Lourival Marin;Trugilho, Paulo Fernando;Cardoso, Maria das Gra?as;
Ciência e Tecnologia de Alimentos , 2003, DOI: 10.1590/S0101-20612003000300018
Abstract: the aim of this work was to evaluate different species of eucalyptus and of native wood to make barrels for storage of sugar cane spirit. it was studied the chemical, anatomical and physical properties of the woods and made physical-chemical analyses of the sugar cane spirit storage during twelve months. the barrels made with wood of eucalyptus presented little permeabilidade to liquids and a low dimensional estability, provoking discard of great part of them. the chemical composition of the different eucalyptus wood showed constant polissacarydes and lignina contents but differing among extractives levels, that were higher than the oak wood. the composition of the sugar cane spirit stored in these kind of wood showed pattern according to the brazilian law, indicating their potential use as barrels for the storage of sugar cane spirit. the native wood, also showed low dimensional instability with no leaking, constant polyssacarydes and lignina contents and higher extractive levels than oak wood. the sugar cane spirit composition after storage was also according to the law.
Propriedades e classifica??o da madeira aplicadas à sele??o de genótipos de Eucalyptus
Caixeta, Ronaldo Pereira;Trugilho, Paulo Fernando;Rosado, Sebasti?o Carlos da Silva;Lima, José Tarcísio;
Revista árvore , 2003, DOI: 10.1590/S0100-67622003000100006
Abstract: the objective of this study was to classify and select superior genotypes of eucalypt based on the properties of its wood, utilizing cluster analysis, the tocher's optimization method aiming to obtain various products. forty-four genotypes adapted to the environmental conditions of northwestern minas gerais were used. physical, mechanical resistance and chemical wood characteristics were used for the classification of the materials. cluster analysis classified the genotypes in 11 different groups with high variability or divergence among them. according to the average values of the characteristics presented by the formed groups, it was possible to define new potential clones, which will certainly provide wood of superior quality. the genotypes from groups v, vi and viii show potential for the production of sawed wood, also facilitating the generation of natural hybrids, which may be used in future programs of genetic improvement of eucalyptus.
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