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Comparative anatomy of the wood of Abies pinsapo and its two moroccan varieties. IAWA Journal. 28(3): 285-298.


Abstract: This study describes the structure of the wood of Abies pinsapo from samples taken from its three natural distribution areas in the Iberian Peninsula (Sierra de Grazalema, Sierra de las Nieves and Sierra Bermeja) and compares them with the varieties from the north of Africa, Abies pinsapo var. marocana from the Talassemtane mountains and A. pinsapo var. tazaotana from the Tazaout mountains. All the samples were collected in their regions of provenance. To put the results into perspective, a comparison was also made with the wood of Abies alba and A. numidica. The wood of the Iberian A. pinsapo and of its two varieties from the Rif mountains in Morocco is anatomically similar, and there are no qualitative differences that enable the wood to be differentiated except for the presence of resin deposits in the tracheids adjacent to the rays in the samples from Grazalema. Quantitatively, for tracheid diameter and tracheid length there are statistically significantly differences (p < 0.05) between those of Spanish provenance and the Moroccan varieties, but for tracheid pit diameter, largest diameter of cross-field pits and tall ray frequency the samples from Sierra Bermeja have more in common with the African samples.

 

Sorption and thermodynamic properties of old and new Pinus sylvestris wood. Wood and Fiber Science. 40(1): 111-121.



Abstract: The 35 degrees and 50 degrees C isotherms of juvenile Pinus sylvestris L. wood from recently cut trees were compared with those of juvenile wood of the same species previously forming part of an 18(th) century wooden building in order to determine the thermodynamic properties of the two types of wood through the isotherms. The isotherms were plotted using the gravimetric method of saturated salts in the water activity range of 0.11 to 0.97 for the 35 degrees C isotherm and 0.11 to 0.96 for the 50 degrees C isotherm. The sorption curves were fitted using the GAB method, and the isosteric heat of sorption was obtained by means of the integration method of the Clausius-Clapeyron equation. In both types of wood, the net isosteric heat decreases as the moisture content of the specimen increases, and the maximum values of isosteric heat in the new wood are greater than in the old wood, both in adsorption and desorption. This indicates that the bond energy in the new wood is greater than in the old wood.

 

Variation of impact bending in the wood of Pinus sylvestris L. in relation to its position in the tree. Forest Products Journal. 58(3): 55-60.



Abstract: The response of the wood of Pinus sylvestris L. to impact bending using the Charpy method was studied in 2940 defect-free, oriented test pieces from the central board of 10 trees felled during scheduled cutting, with the values obtained being related to the position of the test piece in the tree, both from the pith to the outside and in terms of its height in the tree. For this purpose the absorbed energy was obtained by using an instrumented drop-weight impact tester. The tests were carried out in stable hygrothermic conditions of 65,5 percent and 22 +/- 2 degrees C, and the wood was conditioned under the same conditions before testing. The characterisation was carried out on test pieces with a cross section of 20 mm by 20 mm and a length of 150 mm. The results obtained show that impact bending decreases the closer the test piece is to the pith and the higher it is in the tree, with the decrease being greater horizontally than vertically. In addition, it was shown that there is a significant relation between the number of rings and the impact response of the wood.

 

Characteristic values of the mechanical properties of radiata pine plywood and the derivation of basic values of the layers for a calculation method. Biosystems Engineering. 99: 256-266.



Abstract: The mechanical properties and characteristic values of radiata pine plywood for structural use were measured using the European standards (EN 789 and EN 1058). Eight different compositions of panels with thicknesses from 9 to 30 mm were tested. Their mechanical properties were found to be similar to those of other plywoods from Europe manufactured with spruce. The test results of plywood showed the mechanical properties of layers (basic values) using the method proposed by European standards. The strength and elasticity modulus of the layers were obtained for bending, tension and compression. it can be concluded that basic values are suitable for estimating the properties of different compositions of plywood.

 

Thermodynamic characterisation of particleboard using sorption isotherms. Wood Research. 53(2): 45-56.



Abstract: The sorption and desorption isotherms of standard particleboard were obtained in this study using the equilibrium moisture contents achieved by applying the gravimetric method of saturated salts at 35 degrees C and 50 degrees C in the water activity range of 0.11 to 0.89. The curves were fitted following the Guggenheim, Anderson and Boer-Dent model, and the isosteric heat of sorption was obtained by means of the Clausius-Clapeyron integration method. The results show that although particleboard has a thermodynamic behaviour which is qualitatively similar to solid wood, its hygroscopic behaviour is nonetheless different, as the monolayer becomes saturated by chemisorption before physisorption starts to prevail over chemisorption.

 

Esteban, L.G.

de Palacios, P.

García Fernández, F.

Guindeo, A. 

Navarro, N.


2008

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Arriaga, F.

Peraza, F.

Esteban, L.G.


2008

de Palacios, P.

Esteban, L.G.

Guindeo A.

García Fernández, F.

Fernández Canteli A.

Navarro N.


2008

Esteban, L.G.

de Palacios, P.

García Fernández, F.

Guindeo A.

Navarro Cano, N.


2008

Esteban, L.G.

de Palacios, P.

Guindeo A.

García Fernández, F.


2007

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MATERIALS:

WOOD and PAPER

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Artículos científicos

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