Автор: Dimitrios Koutsianitis
Статии
- QUANTITATIVE AND QUALITATIVE WOOD PRODUCTION OF FIR (ABIES BORISII-REGIS MATTF.) IN DIFFERENT SITE QUALITIES
-
Резюме
Of the numerous environmental factors affecting tree growth, the relationship between site quality and tree growth seems to be the most important. In this work, the production of fir wood (Abies borisii-regis Mattf.) on quantitative and qualitative basis was investigated in relation to three different site qualities (II, III, IV) at the University forest of Pertouli-Trikala, Greece. For the grading of round timber produced from 268 fir trees, the EN 1927-1:2008 CEN standard was employed. The results showed that the site quality has an influence on both quantitative and qualitative production of fir wood. Higher production and better quality of fir wood were found to be produced in the site quality II, while in the site quality IV, the quantity and quality of wood produced were less and inferior, respectively. In the site quality III, the production and quality of fir wood were at intermediate level.
Ключови думи: fir, wood production, quality of wood, site quality
- EFFECTS OF LASER DRILLING ON MECHANICAL PROPERTIES AND IMPREGNABILITY OF FIR AND SPRUCE WOOD*
-
Резюме
Fir (Abies borisii regis) and spruce (Picea excelsa) wood specimens, 2 × 2 cm in cross section and 34 cm long, were prepared with true radial and tangential surfaces. All lateral surfaces of the specimens were drilled by laser to a depth of 4 mm (1/5 of specimen thickness) with two drilling patterns (distance between holes 1 × 1 cm and 1 × 2 cm). ). After drilling, the mechanical strength of wood (MOE, MOR, axial compression, toughness) was determined and compared with non-drilled controls. MOE was not affected by the laser drilling, MOR was significantly increased, axial compression was increased and toughness was decreased but not significantly. The overall results imply that strength properties do not decline by the laser drilling. Furthermore, wood specimens were impregnated with rape oil and CCB preservatives by applying vacuum (0.6 mmHg) and pressure (1,5 bars) for 15 minutes and 30 minutes, respectively. The results showed that both drilling patterns improved the retention and penetration of preservatives in fir and spruce wood specimens and, thus, are encouraging for further evaluating the drilling effects on the liquid permeability of these refractory to impregnation species. This effect was more pronounced in fir than in spruce wood.
Ключови думи: fir/spruce wood, laser drilling, mechanical strength, impregnability, retention, penetration