<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">FORTES, M A</style></author><author><style face="normal" font="default" size="100%">Rosa, M E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Growth stresses and strains in cork</style></title><secondary-title><style face="normal" font="default" size="100%">Wood science and technology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">back layer</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">growth stresses (voyant)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><volume><style face="normal" font="default" size="100%">258</style></volume><pages><style face="normal" font="default" size="100%">241-258</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A detailed study of the growth stresses and strait~s in the cork sheI1 of the cork-oak was undertaken based on experimentally determined constitutive relations for cork in tension and compression. The stresses depend on the thicknesses of the cork shell and of the back layer around the cork shell, on the radius of the trunk and on its increase due to growth. The circumferential stresses in the cork shell and back layer are tensile and increase with increasing distance to the tree axis. The radial stresses are compressive and decrease with increasing distance to the tree axis. The strains due to growth are not recovered when the cork boards are removed, unless the boards are heated, for example, by immersion in boiling water. Other consequences of the growth stresses are analysed, such as the occurrence of corrugations in the lateral cell walls of cork, the variation of width of the successive growth rings and the occurrence of cracks in the back layer and outer cork layers.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author><author><style face="normal" font="default" size="100%">Rosa, M Emília</style></author><author><style face="normal" font="default" size="100%">FORTES, M A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">THE CELLULAR STRUCTURE OF CORK FROM QUERCUS SUBER L</style></title><secondary-title><style face="normal" font="default" size="100%">IAWA Bulletin</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cell gcometry</style></keyword><keyword><style  face="normal" font="default" size="100%">cell wall corrugations</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">topology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1987</style></year></dates><volume><style face="normal" font="default" size="100%">8</style></volume><pages><style face="normal" font="default" size="100%">213-218</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The main characteristics of the cellular struc- ture of cork from Quercus suber L. are review- ed and comph;mented with new observations of virgin and reproduction cork by scanning electron microscopy. Particular emphasis is given to cell geometry and topology and to the corrugations that are observed in the cell walls. The effect of the growth season in these fea- tures is described. Large variations in cell size, wall thickness ajld corrugations are reported. Key words: Quercus SIlber, cork, cell gcometry, topology, cell wall corrugations.</style></abstract></record></records></xml>