| 1. |
- Čermák, Petr, et al.
(författare)
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The effect of wetting cycles on moisture behaviour of thermally modified Scots pine (Pinus sylvestris L.) wood
- 2016
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Ingår i: Journal of Materials Science. - : Springer Publishing Company. - 0022-2461 .- 1573-4803. ; 51:3, s. 1504-1511
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Tidskriftsartikel (refereegranskat)abstract
- The moisture behaviour of thermally modified Scots pine (Pinus sylvestris L.) exposed to cyclic conditions was analysed. Specimens of dimensions 15 × 15 × 5 mm3 were thermally modified at 180 °C (TM1) and 220 °C (TM2) using atmospheric pressure and superheated steam. Radial, tangential, volumetric swelling and anti-swelling efficiency (ASE) were calculated during six consecutive drying–soaking cycles. Afterwards, additional specimens were exposed to ten relative humidity cycles (0 and 95 %) at temperature 25 and 40 °C in order to analyse its influence on sorption behaviour. Application of thermal modification led to significant reduction of swelling from original 18.4–13.3 % for TM1 and to 10.5 % for TM2. However, after exposure to six consecutive soaking–drying cycles, the swelling of control specimens slightly decreased, whereas the swelling of thermally modified specimens increased. Due to the increased swelling after repeated cycles, the original ASE (28.6 and 42.7 %) decreased to 22.5 % for TM1 and to 36.88 % for TM2. The presence of leachable compounds and release of internal stresses are mainly attributed to that phenomenon. The EMC of the reference specimens decreases over the repeated humidity cycles for approximately 1 %–units. Same trend was found for the mild thermal modification TM1, but decreasing only in the range of 0.5 %–units. However, the EMC of the TM2 specimens during humidity cycles behaved differently. The results provide a better insight into details of thermal modification of wood and its behaviour under cyclic conditions.
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| 2. |
- Rademacher, Peter, et al.
(författare)
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European co-operation in wood research From native wood to engineered materials : Part 3: engineered hybrid wood-based products
- 2017
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Ingår i: Pro Ligno. - Romania : Pro Ligno Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 361-372
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Tidskriftsartikel (refereegranskat)abstract
- Forest-based industries have been continuously developing advanced processes, materials and wood-based solutions, to meet evolving demands and increase competitiveness. Engineered wood products (EWPs) constitute one emerging group of materials aiming at improved property profiles of wood, and provide desired shapes and functionality. In this paper, the main principles for different processes to soften wood and make it more flexible for bending and moulding, such as longitudinal compression, plasticization by water vapour and gaseous ammonia, and a dielectric heating technique, are discussed. Examples of implementation of these techniques for the production of wooden products are presented, and the use of reed canary grass, and a novel technique for embossment of hybrid particleboards are also further discussed.
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| 3. |
- Cermak, Petr, et al.
(författare)
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Optimizing Monochromatic Focusing on ThALES
- 2013
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Ingår i: Journal of the Physical Society of Japan. - 1347-4073. ; 82, s. 026-026
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Tidskriftsartikel (refereegranskat)abstract
- Neutron ray-tracing simulations have been done in order to study the interplay between an elliptically shaped guide end with two double focusing monochromators - pyrolytic graphite PG002 and bent Si111. The primary aim of these calculations has been the optimisation of the neutron optics of the new cold triple-axis spectrometer ThALES, the successor of the IN14 spectrometer at the Institut Laue-Langevin, Grenoble. The obtained results are, nevertheless, general and independent of the specific geometry of ThALES. The beam characteristics in terms of flux, real space and angular distribution and energy resolution at the sample position are presented for both cases.
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