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.

Mensuração do comprimento das fibras para a determinação da madeira juvenil em Eucalyptus citriodora

The juvenile wood has peculiar characteristics from the anatomical structure and physical-mechanical properties, considering these aspects the knowledge of the wood is essential for wood adequate utilization. The aim of this work was to determinate the zone of juvenile wood of pith-bark direction in Eucalyptus citriodora. The juvenile and mature wood zones were determined across fiber length measurement in various height in the tree stem. Results showed that juvenile wood zone occurs approximately up to the 45 at 55 mm from the pith.

Protagonismo juvenil en proyectos locales: lecciones del Cono Sur

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Participación juvenil y ciudadanía

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Programa de empleo juvenil: Encuentro de Mejores Prácticas con Jóvenes del Cono Sur

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Mercado de trabajo juvenil: situación y políticas

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Magnitud y heterogeneidad: políticas de fomento del empleo juvenil y las micro y pequeñas empresas

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Hacia la construcción de lecciones del posconflicto en América Latina y el Caribe: una mirada a la violencia juvenil en Centroamérica

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Violencia escolar y juvenil: un intento por comprender sus motivaciones

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Metodologias de pesquisa para o estudo geográfico da sociabilidade juvenil

This study aims to present the methodologies of research used to carry out the dissertation requirements related to the different times and spaces linked to the youth sociability. The methodologies are about qualitative features not at all unknown to the geography studies despite the little account taken on them. The methodologies are: eyewitness accounts, Oral History, interviews and groups of debate. With this purpose, this work intends to bring some contribution to geographers and beginners that have been looking for methodological references to their researches it also tries to facilitate the discussion on the methodological dimension in the geographical studies.

America Central: estimaciones de la mortalidad infantil y juvenil. Aplicacion de la tecnica de Brass y las variantes de Sullivan y Trussell, 1970

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Delimitação entre os lenhos juvenil e adulto de pinus elliottii engelm

Trees produce different types of woody tissue during growth. The xylem produced in the first years until a certain cambial age is called juvenile wood and has different physical, mechanical, chemical and anatomical characteristics from that produced later, when the cambial cells have matured. Thus, prior knowledge of the quality of the wood is of fundamental importance for choosing the best use of the material. This work aimed at using data from length of the tracheid and wood density to define the age transition from juvenile to mature wood. For this, three Pinus elliottii var. elliottii trees, aged 35 years, were collected at the Itapetininga Experimental Station, located in the state of São Paulo, Brazil. From each tree, disks of about 5 cm thick were obtained 0.05 m above the ground and used to determine the radial density by the gamma ray attenuation method and to measure the length of the tracheids. The results obtained by linear regression analysis showed that juvenile wood is limited to the first seven years of tree growth and the formation of mature wood occurs after twenty years. For the mature wood, there are significant differences among the averages obtained from the tracheid length and wood density.

Los desafíos de fin de siglo y la problemática juvenil rural en América Latina

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Los desafíos de fin de siglo y la problemática juvenil rural en América Latina

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