| 1. |
- Bjurhager, Ingela, et al.
(författare)
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Ultrastructure and Mechanical Properties of Populus Wood with Reduced Lignin Content Caused by Transgenic Down-Regulation of Cinnamate 4-Hydroxylase
- 2010
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 11:9, s. 2359-2365
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Tidskriftsartikel (refereegranskat)abstract
- Several key enzymes in lignin biosynthesis of Populus have been down-regulated by transgenie approaches to investigate their role in wood lignification and to explore their potential for lignin modification. Cinnamate 4-hydroxylase is an enzyme in the early phenylpropanoid pathway that has not yet been functionally analyzed in Populus. This study shows that down-regulation of cinnamate 4-hydroxylase reduced Klason lignin content by 30% with no significant change in syringyl to guaiacyl ratio. The lignin reduction resulted in ultrastructural differences of the wood and a 10% decrease in wood density. Mechanical properties investigated by tensile tests and dynamic mechanical analysis showed a decrease in stiffness, which could be explained by the lower density. The study demonstrates that a large modification in lignin content only has minor influences on tensile properties of wood in its axial direction and highlights the usefulness of wood modified beyond its natural variation by transgene technology in exploring the impact of wood biopolymer composition and ultrastructure on its material properties.
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| 2. |
- Chang, Shan-Shan, et al.
(författare)
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Deposition and organisation of cell wall polymers during maturation of poplar tension wood by FTIR microspectroscopy
- 2014
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Ingår i: Planta. - : Springer Science and Business Media LLC. - 0032-0935 .- 1432-2048. ; 239:1, s. 243-254
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Tidskriftsartikel (refereegranskat)abstract
- To advance our understanding of the formation of tension wood, we investigated the macromolecular arrangement in cell walls by Fourier transform infrared microspectroscopy (FTIR) during maturation of tension wood in poplar (Populus tremula x P. alba, clone INRA 717-1B4). The relation between changes in composition and the deposition of the G-layer in tension wood was analysed. Polarised FTIR measurements indicated that in tension wood, already before G-layer formation, a more ordered structure of carbohydrates at an angle more parallel to the fibre axis exists. This was clearly different from the behaviour of opposite wood. With the formation of the S2 layer in opposite wood and the G-layer in tension wood, the orientation signals from the amorphous carbohydrates like hemicelluloses and pectins were different between opposite wood and tension wood. For tension wood, the orientation for these bands remains the same all along the cell wall maturation process, probably reflecting a continued deposition of xyloglucan or xylan, with an orientation different to that in the S2 wall throughout the whole process. In tension wood, the lignin was more highly oriented in the S2 layer than in opposite wood.
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| 3. |
- Claesson, Åsa, et al.
(författare)
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Novel design for diode-pumped miniature lasers using microstructured silicon carriers
- 2000
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Ingår i: Advanced Solid State Lasers. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- A new design concept for compact diode-pumped solid-state lasers is presented. The design is based on a microstructured silicon carrier with etched v-grooves. This silicon microbench provides efficient thermal management at 10W pumping level, as well as compact integration and alignment of all active and passive optical components of compact diode-pumped solid-state lasers. In initial experiments, a Nd:YAG laser built on the microbench delivered a continuous-wave output of 3W.
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| 4. |
- Dong, F., et al.
(författare)
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Fibre morphological effects on mechano-sorptive creep
- 2010
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 0043-7719 .- 1432-5225. ; 44:3, s. 475-483
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Tidskriftsartikel (refereegranskat)abstract
- The increased creep rate of paper under load during moisture cycling conditions as compared to that at high constant humidity is a problem in the use of packaging materials. In order to investigate the influence of morphological factors of the fibres on the occurrence and magnitude of this phenomenon, i.e. the occurrence of mechano-sorptive creep, studies on wood fibres isolated from different parts of spruce wood were performed. Thus, creep properties were studied on earlywood and latewood fibres from both juvenile wood and mature wood. In general, latewood fibres showed a higher degree of mechano-sorptive creep than earlywood fibres, and mature wood showed a higher degree of mechano-sorptive creep than juvenile fibres. The difference in mechano-sorptive creep rate between different fibres was shown to be correlated to the differences in fibril angle. The smaller the fibril angle the higher was the mechano-sorptive creep ratio. It was suggested that at fibril angles approaching 45° wood fibres do not exhibit mechano-sorptive creep.
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| 5. |
- Fahnestock, Jesse, 1974-, et al.
(författare)
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RISEnergy: Roadmaps for energy innovation in Sweden through 2030
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- RISE Research Institutes of Sweden is a group of research and technology organisations. RISE is a leading innovation partner working global cooperation with academia, enterprise and society to create value, growth and competitiveness through research excellence and innovation.In the area of Energy, RISE has developed innovation Roadmaps covering:Energy Efficient TransportElectric Power SystemEnergy Efficient and Smart BuildingsSustainable Thermal ProcessesEfficient Energy Use in IndustryDecarbonisation of Basic IndustriesThese Roadmaps describe development pathways for technologies, non-technical elements (market design, user behaviours, policies, etc.) and key actors that deliver on a plausible, desirable vision for each respective innovation area in 2030. These Roadmaps are intended to support RISE’s strategic planning and development, but should be relevant reading for anyone interested in energy innovation in Sweden.
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| 6. |
- Lundström, Anton, et al.
(författare)
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Enough power to move : Dimensions for representing energy availability
- 2012
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Ingår i: MobileHCI'12 - Proceedings of the 14th International Conference on Human Computer Interaction with Mobile Devices and Services. - New York, NY, USA : ACM. - 9781450311052 ; , s. 201-210
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Konferensbidrag (refereegranskat)abstract
- Energy and design of energy-feedback are becoming increasingly important in the mobile HCI community. Our application area concerns electric vehicles. We thus depart from home and workplace appliances and address range and energy anxiety caused by short driving distance capabilities and long charging times in mobile settings. While some research has been done on energy management of mobile devices, less has been done on mobility devices like electric vehicles. We explore this topic by letting conventional fuel car drivers reflect on their current driving habits through an exploration tool that we developed. Our results demonstrate three dimensions related to energy availability to consider for design of energy dependent mobility devices and provide explanations on how these dimensions could be utilize in our design through energy visualizations. With this we contributed not only by demonstrating aspects of energy availability and mobility, but also through opening up for new interesting possibilities and inquires in our and possibly other domains.
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| 7. |
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| 8. |
- Olsson, Anne M., et al.
(författare)
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Mechano-sorptive creep in pulp fibres and paper
- 2014
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 0043-7719 .- 1432-5225. ; 48:3, s. 569-580
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Tidskriftsartikel (refereegranskat)abstract
- The factors affecting mechano-sorptive creep of wood and paper have been investigated for a long time. It has also been argued that single wood fibres do not exhibit mechano-sorptive creep and that the reasons for the accelerated creep under moisture cycling conditions instead are related to the bonds between the fibres. In order to examine the relevance of this argument, measurements on single pulp fibres of different composition were performed in tension, and the mechano-sorptive creep was compared to that of papers made from the same source of pulp fibres. All fibres tested were found to exhibit an increased creep rate during moisture cycling as compared to constant humidity conditions. Thus, pulp fibres show mechano-sorptive creep and in this sense behave similar to solid wood or paper products made thereof. A linear relation between the creep strain rate during cyclic humidity and the creep strain rate at a constant humidity was also noted for both fibres and paper. This relation was not affected by changes in hemicelluloses content or composition, neither for fibres nor for papers made of these fibres. However, in all cases, papers showed a much higher mechano-sorptive creep than the corresponding fibres they were made of.
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| 9. |
- Olsson, Anne-Mari, et al.
(författare)
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Ultra-structural organisation of cell wall polymers in normal and tension wood of aspen revealed by polarisation FTIR microspectroscopy
- 2011
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Ingår i: Planta. - : Springer Science and Business Media LLC. - 0032-0935 .- 1432-2048. ; 233:6, s. 1277-1286
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Tidskriftsartikel (refereegranskat)abstract
- Polarisation Fourier transform infra-red (FTIR) microspectroscopy was used to characterize the organisation and orientation of wood polymers in normal wood and tension wood from hybrid aspen (Populus tremula x Populus tremuloides). It is shown that both xylan and lignin in normal wood are highly oriented in the fibre wall. Their orientation is parallel with the cellulose microfibrils and hence in the direction of the fibre axis. In tension wood a similar orientation of lignin was found. However, in tension wood absorption peaks normally assigned to xylan exhibited a 90A degrees change in the orientation dependence of the vibrations as compared with normal wood. The molecular origin of these vibrations are not known, but they are abundant enough to mask the orientation dependence of the xylan signal from the S-2 layer in tension wood and could possibly come from other pentose sugars present in, or associated with, the gelatinous layer of tension wood fibres.
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| 10. |
- Olsson, Mats, et al.
(författare)
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NORDJUST-audit.
- 1997
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Rapport (refereegranskat)
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