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Deposits from different sections of a newsprint paper mill, using 100% recovered paper, were analyzed following an analytical procedure based on SEM-EDX and consecutive solvent extraction steps with FTIR analyses of the different fractions. Polyvinyl acetate, polyacrylates, styrene butadiene rubber and derivatives of fatty acids/resin acids are the main stickies-related components identified in the deposits. The removal efficiency of these contaminants along the deinking line was studied by determining the composition of the dichloromethane extractives in the pulp by FTIR analyses. Although the total stickies content is reduced considerably during the process, some compounds, which are found in the deposits, are not removed selectively in the process, indicating their recalcitrant nature. FTIR analyses of unusable materials coming with the raw material (mainly board and mixed office waste), have demonstrated these materials are one of the main sources of these type of recalcitrant stickies.

An evaluation of 100 Eucalyptus globulus and 100 E. nitens trees (six years old) was made using the Pilodyn micro-drilling tool as an indicator of wood density. Thirty E. globulus and thirty E. nitens trees with high, medium and low density were selected and sampled with an increment borer at breast height for anatomical analysis using fibre tester equipment and the Resistograph device to generate detailed information about fibre biometry and anatomical wood properties of both species for hybrid development. Eucalyptus globulus trees had a basic wood density average of 478 kg/m3, while E. nitens had a density of 490 kg/m3. Both micro-drilling tools showed significant correlation coefficients with basic wood density. Correlation coefficients between basic wood density and Pilodyn values were negative, being -0.53 (p = 0.01) and -0.68 (p < 0.001) for E. globulus and E. nitens, respectively. For both species a positive correlation was observed between basic density and Resistograph mean amplitude; the correlation coefficient was 0.84 (p < 0.001) for E. globulus, and 0.85 (p < 0.001) for E. nitens. Eucalyptus nitens trees had a higher density and amplitude average and smaller Pilodyn values than E. globulus trees, while the latter had higher coarseness, fibre length and diameter at breast height than E. nitens trees. However, E. nitens showed larger differences between features of earlywood and latewood in a growth ring than E. globulus trees.

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The dielectric breakdown of solid polymeric materials is due to the inception and propagation of electrical trees inside them. The remaining useful life of the solid dielectrics could be determined using propagation simulations correlated with non-intrusive measurements such as partial discharges (PD). This paper presents a brief review of the different models for simulating electrical tree propagation in solid dielectrics. A novel improved physical-stochastic model is proposed, which allows quantitatively and qualitatively analyzing the electrical tree propagation process in polymeric dielectrics. Simulation results exhibit good agreement with measurements presented in the literature. It is concluded that the model allows adequately predicting the tree propagation behavior and additional experimental analyses are required in order to improve the model accuracy.

Brachystegia spiciformis and Pericopsis angolensis are two hardwood species found in the Miombo woodlands. The wood features, kraft pulping and strength pulp properties of both species were evaluated in order to determine their potential as raw material for papermaking. Brachystegia spiciformis wood density was 640 kg m -3and Pericopsis angolensis was 795 kg m -3. Pericopsis angolensis wood has higher cell wall thickness and occluded fibre lumen as remarkable anatomical properties. Runkel ratio, slenderness ratio, and the coefficients of flexibility and rigidity in Brachystegia spiciformis were 1,5; 65,7; 41,2% and 29,4% while in Pericopsis angolensis these values were 17,6; 59,9; 5,4% and 47,3%, respectively. Brachystegia spiciformis has a higher cellulose content, lower hemicellulose and lignin content, and higher S/G ratio than Pericopsis angolensis. In kraft pulping, a higher demand of active alkali was needed for both species, and pulps with high kappa number (24-27) and low pulp yield (40%) were obtained. Pericopsis angolensis pulps reached tensile, tear and burst indexes of 99,6 Nm g -1 ; 5,9 mN.m 2 g -1 and 4,9 kPa.m 2 g -1 , respectively. Brachystegia spiciformis pulps reached tensile, tear and burst indexes of 100,3 Nm g -1 ; 10,7 mN.m 2 g -1 and 6,1 kPa.m 2 g -1 , respectively. As a conclusion, Brachystegia spiciformis wood has better pulpability than Pericopsis angolensis wood, according to its pulps properties, despite of the similar pulp yield between both species. Both species may be suitable for unbleached wrapping papers and rigid cardboards manufacturing.

La técnica de discusión de dilemas se presenta en el marco de las teorías cognitivo-evolutivas, haciendo referencia a la teoría de los LAS TEORIAS COGNITIVO-EVOLUTIVAS SOBRE EL DESARROLLO MORAL: L. KOHLBERGLas teorías cognitivo-evolutivas, a diferencia de las concepciones que consideran el desarrollo moral como el proceso de internalización de las normas sociales, sostienen que tal desarrollo se basa en la adquisición de principios autónomos de justicia, fruto de interacciones sociales caracterizadas por el diá-logo, la cooperación y el respeto a los derechos de los demás.El carácter «cognitivo» de estas teorías supone reconocer que la educación moral, al igual que la intelectual, tiene sus bases en la estimulación del pensamiento activo del niño y de la niña sobre cuestiones morales. Junto a ello, el término «evolutivo» permite entender los fines de la educación moral como un movimiento a través de estadios l .L. Kohlberg se enmarca en estos enfoques cognitivo-evolutivos. Nacido en 1927, y formado en la Universidad de Chicago, Kohlberg es uno de los muchos psicólogos americanos atraídos por la obra piagetiana en los arios 50. Su trabajo es una profundización y extensión de las aportaciones de Piaget en «El criterio moral en el niño», incorporando las posteriores investigaciones que éste realizó en el campo de las categorías lógicas. La obra de Kohlberg, vinculada directamente con la teoría de Piaget, recibe también importantes influencias de diferentes filósofos, sociólogos y psicólogos (Kant, Baldwin, Mead, Dewey...). Su contribución especial ha sido aplicar el concepto de desarrollo por estadios que Piaget elaboró para el desarrollo cognitivo, al estudio del juicio moral 2 . En esComunicación, Lenguaje y Educación, 1992, 15, 55-62

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