Propriedades físicas dos lenhos juvenil e adulto de Pinus elliottii Engelm var. elliottii e de Eucalyptus grandis Hill ex Maiden

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.

Application of X-ray technique in nondestructive evaluation of eucalypt wood

X-rays were initially used for the inspection of special-purpose wood pieces for quantitative evaluation properties of different species. X-ray densitometry has had its use expanded ill dendroclimatology of Picea engelmannii trees. Subsequent laboratories developed applications of X-ray densitometry for environmental, wood science and technology, and related areas. This paper describes the basic methodology of X-ray densitometry applied to the eucalypt wood analysis, as well its presenting the results of applications in three areas: (i) evaluation of wood biodegradation by white rot fungi, (ii) detection of sapwood and heartwood, and (iii) determination of the effect of management oil wood properties. The wood decayed by white rot fungi was detected by X-ray densitometry with it decreasing wood density due to the biodegradation of cell wall components. The sapwood and heartwood of eucalypts were separated in response to the attenuation of X-rays, reflected by the wood anatomical structure and chemical composition. Also, Ill eucalypt trees after the application of irrigation and i characteristic wood density profiles were detected. Ill addition, the significant potential of X-ray densitometry for eucalypt wood research and analysis is discussed.

Determinação do módulo de elasticidade da madeira juvenil e adulta de Pinus taeda por ultra-som

A madeira de Pinus sp. tem utilização crescente na indústria madeireira brasileira. O decréscimo constante do suprimento de árvores adultas com grandes diâmetros, provenientes de florestas naturais, tornou comum a produção de madeira em ciclos curtos, com grande proporção de madeira juvenil. Resultados de diversas pesquisas têm reportado que o módulo de elasticidade e a resistência a diferentes solicitações mecânicas são seriamente afetados pela presença de madeira juvenil. Este trabalho teve por objetivo determinar o módulo de elasticidade da madeira juvenil e adulta de Pinus taeda L. a partir da constante dinâmica C LL, obtida em ensaios não-destrutivos de ultra-som. A madeira de P. taeda era originária de plantios da Estação Experimental de Itapeva - SP, sendo amostrados seis indivíduos arbóreos com 34 anos de idade. Os corpos-de-prova (4 cm x 4 cm x 45 cm) foram obtidos separadamente das regiões de madeira juvenil e adulta da prancha central, previamente submetida à secagem industrial (umidade final de 12%), para a determinação da constante dinâmica por meio de ensaios de ultra-som. Para avaliar a sensibilidade do método do ultra-som, os corpos-de-prova foram ensaiados destrutivamente à compressão paralela. Os resultados mostraram boa sensibilidade do método do ultra-som (R² » 0,90) na avaliação desse parâmetro mecânico da madeira juvenil e adulta.

Decay resistance of thermally-modified Eucalyptus grandis wood at 140 degrees C, 160 degrees C, 180 degrees C, 200 degrees C and 220 degrees C

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

Imbibition damage in soybean seeds as affected by initial moisture content, cultivar and production location

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seasonal variation in wood formation of Cedrela fissilis (Meliaceae)

Cambial activity and periodicity of secondary xylem formation in Cedrela fissilis, a semi-ring-porous species, were studied. Wood samples were collected periodically from 1996 to 2000. The phenology was related to climate data of the region. The cambium has one active and one dormant period per year. The active period coincides with the wet season when trees leaf-out. The dormant period coincides with the dry season when trees lose their leaves. Growth rings are marked by parenchyma bands that begin to be formed, together with the small latewood vessels, just before the cambium becomes dormant at the beginning of the dry season. These bands are added to when the cambium reactivates in the wet season. At this time, the large earlywood vessels of the growth rings are also formed. As these bands consist of both terminal and initial parenchyma, we suggest the general term marginal bands be used to describe them. The growth layers vary in width among and within the trees.

A comparison of the wood anatomy of 11 species from two cerrado habitats (cerrado s.s. and adjacent gallery forest)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

THE EFFECT of CARBONIZATION on WOOD STRUCTURE of DALBERGIA VIOLACEA, STRYPHNODENDRON POLYPHYLLUM, TAPIRIRA GUIANENSIS, VOCHYSIA TUCANORUM, and POUTERIA TORTA FROM THE BRAZILIAN CERRADO

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Physical and chemical changes in juvenile and mature woods of Pinus elliottii var. elliottii by thermal modification

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

Influence of belt speed, grit sizes and pressure on the sanding of Eucalyptus grandis wood

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

The Temperature and Humidity in a Low-Flow Anesthesia Workstation With and Without a Heat and Moisture Exchanger

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nutritive value of high and low tanin content of sorghum high moisture silage for horses

Foram utilizados oito cavalos castrados sem raça definida em delineamento inteiramente casualizado. O objetivo foi determinar o valor nutritivo das silagens de grãos de sorgo de baixo (SBT) e alto (SAT) teores de tanino na alimentação de equinos. Os tratamentos consistiram de duas dietas-teste compostas pelos grãos de sorgo ensilados (SBT e SAT), substituindo em 30% a MS da dieta-referência, constituída exclusivamente por feno. Os valores de digestibilidade dos nutrientes dos SBT e SAT apresentaram diferenças nos CDMS, CDMO, CDEB, CDPB e CDAmido em que SAT foi inferior (p < 0,05) para todos os parâmetros, em que os valores médios foram de, respectivamente, 79,53, 84,54, 79,36, 76,11 e 100% para SBT e 60,29, 64,47, 59,38, 44,63 e 97,06% para SAT. Concluiu-se que a utilização do SBT é promissora na nutrição de equinos, tornando-se alimento alternativo nas formulações de rações.

Use of high moisture corn silage replacing dry corn on intake, apparent digestibility, production and composition of milk of dairy goats

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

Selecting appropriate bedding to reduce locomotion problems in broilers

Two experiments were carried out at the Poultry Sector of the School of Agrarian Sciences of the Federal University of Grande Dourados to evaluate the incidence of leg problems in broilers reared on two distinct types of bedding material: rice husks or wood shavings, both new and reused. In both trials, a randomized experimental design was applied in factorial arrangement (2 x 2 x 2) using two genetic strains (Cobb® or Ross®); two sexes (male or female), and two litter materials (rice husks or wood shavings). In each trial 1080 one day pullets were reared equally divided in the treatments. The birds were placed in 4.5 m² boxes at a density of 10 birds m-2. All birds were fed diets with equal nutritional density, and water was offered ad libitum. Feeds were divided in three phases: starter diet (1 - 21 days), grower diet (22 - 35 days), and finisher diet (36 - 45 days). on day 45, fifty birds were randomly selected in each experiment to evaluate flock leg problems. The following parameters were analyzed: gait score, incidence of valgus and varus disorder, footpad dermatitis, femoral degeneration, tibial dyschondroplasia, and spondylolisthesis. Ambient temperature during rearing and litter caking and moisture content were recorded in four boxes per treatment. The analytical hierarchy process was used to organize the data into specific criteria. Several criteria, related to the attributes that were determinant according to the statistical analysis, were chosen in order to provide the best input to the process. Results indicated that new wood-shavings bedding was the most appropriate bedding to prevent locomotion problems, followed by new rice husks, reused wood shavings, and reused rice husks. However, when leg problems were associated to sex and genetic strain, male Ross birds strain presented less problems when reared on new rice husks, followed by new wood shavings

Structural variations in root and stem wood of Styrax (Styracaceae) from Brazilian forest and cerrado

The genus Styrax L. (Styracaceae) has a wide distribution in Brazil, occurring in diverse ecosystems. To get a better insight into the ecological adaptations of wood structure, we studied two species, S. camporum and S.ferrugineus from the cerrado, and three species, S. latifolium, S. martii and S. leprosus from the Atlantic forest. For each species, the wood of root and stem was analyzed separately and observations included qualitative as well as quantitative wood characteristics. The results show that there were significant anatomical differences between the forest and cerrado species as well as between the root and stem wood within single species. Quantitatively, the most informative features in the root wood that separated the forest from the cerrado, species were diameter, length and number of vessels, length of fibres, and width and frequency of rays. In the stem wood, length and frequency of vessels, length of fibres, and width and frequency of rays were the most informative features. In contrast to the forest species, which had larger vessel diameters in their stem wood, the cerrado species had larger vessel diameters in their root wood. The calculated vulnerability index indicates that all Sryrax species have adaptations to mesic conditions. The cerrado species had the smallest index values, which could be related to the seasonally dry condition of this environment.