No abstract

Ten 22 year old radiata pine trees growing in two stands in Chile, one in clay and the other in humid sand soils showing some lean, were assessed for chemical composition and wood density of compression wood.Signifi cant differences in type of wood in density (33 kg/m 3 ), lignin (1.944 %), alpha-cellulose (-2.634 %), ethanol toluene extractives (0.567 %) and pentose (0.742 %) were found between matched sample of compression and opposite woods.Differences in juvenile and mature wood were signifi cant for both density (-4 kg/m 3 ) and pentose (1.628 %), and site differences were found for wood density (28 kg/m 3 ), extractives (0.978 %) and apparent for alpha cellulose (1.223%).In comparison with other studies, our results suggested that the compression wood formed from trees with light visible lean corresponded to a mild compression class. Keywords:Compression wood, radiata pine, basic density, lignin, holocellulose, alpha-cellulose, pentose, ethanol-toluene, ash RESUMEN Se analizó la madera de compresión en diez árboles de 22 años de edad de Pinus radiata D Don creciendo en dos sitios en Chile, uno en suelo de arena húmeda y el otro en suelo arcilloso. Singularidades de la madera de compresión y madera opuesta se compararon en estos árboles con inclinaciones menores a 10º y excentricidades reducidas.Diferencias signifi cativas se registraron entre madera de compresión y opuesta en los valores registrados para la densidad básica de 33 (kg/m 3 ), en proporción de lignina de 1.944 (%), en alfa-celulosa de -2.634 (%), en pentosanos de 0.742 (%) y en extraíbles en etanol-tolueno de 0.978 (%) y aparentemente diferente en el caso de alfa celulosa en 1.223 (%).Las diferencias entre madera juvenil y madera madura fueron signifi cativas en los casos de la densidad de -4 (kg/m 3 ) y en pentosanos en 1.628 (%), y diferencias entre los dos sitios para los casos de la densidad con 28 (kg/m 3 ), en extractivos con 0.978 (%) y diferencias moderadas en alfa celulosa con 1.223 (%). Las diferencias y coincidencias de estos resultados con los de otros autores se han considerado para estimar que la madera de compresión formada por estos árboles, con inclinaciones reducidas, correspondería al tipo de madera de compresión leve.

Conceptually, the hospital self-management policy is based on financial autonomy, and implementation is affected by persistent capacity gaps in policy design.

No abstract

Influence of the extractives of selected extraneous woods on the equilibrium moisture content Abstract The water vapour sorption behaviour of 13 different tropical wood species was examined. The experimentally determined values were analysed with the HailwoodHorrobin sorption model. According to the HailwoodHorrobin model the following characteristic values were computed: the monomolecular U m and polymolecular U p sorption, the fiber saturation point U fs , the inaccessibility Z of the sorbent to the sorbate as well as the specific surface of the sorbent Σ. Very large differences exist in the sorption behaviour between the individual wood species. In particular for Canalete (22.8%), Wengé (20.3%) and Doussié (17.8%) a very low fiber saturation point was determined, which is clearly below the values of European wood species (28%-32%) and other examined tropical woods. The ethanol toluol extract of the wood correlates with the moisture content of the polymolecular U p and total U tot sorption. The higher the extractives content the lower the equilibrium moisture content U tot and U p . The extractives show no influence on the monomolecular-bound water U m . The chemisorption remains therefore uninfluenced by EtOH-toluol extractives. The reduction of the sorption capacity by rising EtOH-toluol extractive content is due to the bulking effect.