Effects of an innovative densification process on mechanical and physical properties of beech and Norway spruce veneers

AbstractIncreased wood density is obtained by compressing the wood porous structure under suitable moisture and temperature conditions to improve its physical, mechanical and color properties. A recently proposed wood densification method based on partial removal of lignin and hemicellulose in hot water solution of sodium hydroxide and sodium sulphite has shown promising results on solid wood. However, its applicability and effect on thin wood veneers have not been tested yet. In this study, the timing of the method has been adapted to estimate the densification treatment intensity dependence of wood properties (wood density and modulus of elasticity) and color change of softwood (Norway spruce) and hardwood (beech) veneers. Compared to control, density and rigidity increased, with improved wood properties peaking after only 90 s of treatment intensity. Furthermore, the color became darker after treatment compared to control, with no significant color difference between treatment intensities. In conclusion, densification of veneers, according to the presented adapted method, provides a significant improvement of veneers physical and mechanical properties, and produces color changes perceptible by the human eye. Our results can be further implemented and adapted to application in industrial plants, calling for new application of densified veneers.</jats:p

Les différentes versions de la « découverte » du clitoris par Helen O’Connell (1998-2005)

Between 1998 and 2005, Australian urologist Helen E. O’Connell published a series of scientific articles about her research on the anatomy of the clitoris. In a singular way, she presented her results in a critical narrative denouncing a production of anatomical knowledge biased in terms of gender. After presenting the issues of this research, such as the visual representation of the clitoris, this article looks at the media popularization, which qualified these results as a “discovery.” Finally, this article also questions this reception and the question of the multiple historical claims to the discovery of the female organ. The analysis of narratives circulating in different contexts of knowledge production illuminates a (re-) signification of the clitoris, and by extension of female sexuality, at the turn of the twenty-first century

Les différentes versions de la « découverte » du clitoris par Helen O’Connell (1998-2005)

Between 1998 and 2005, Australian urologist Helen E. O’Connell published a series of scientific articles about her research on the anatomy of the clitoris. In a singular way, she presented her results in a critical narrative denouncing a production of anatomical knowledge biased in terms of gender. After presenting the issues of this research, such as the visual representation of the clitoris, this article looks at the media popularization, which qualified these results as a “discovery.” Finally, this article also questions this reception and the question of the multiple historical claims to the discovery of the female organ. The analysis of narratives circulating in different contexts of knowledge production illuminates a (re-) signification of the clitoris, and by extension of female sexuality, at the turn of the twenty-first century

Effects of an innovative densifcation process on mechanical and physical properties of beech and Norway spruce veneers

Increased wood density is obtained by compressing the wood porous structure under suitable moisture and temperature conditions to improve its physical, mechanical and color properties. A recently proposed wood densifcation method based on partial removal of lignin and hemicellulose in hot water solution of sodium hydroxide and sodium sulphite has shown promising results on solid wood. However, its applicability and effect on thin wood veneers have not been tested yet. In this study, the timing of the method has been adapted to estimate the densifcation treatment intensity dependence of wood properties (wood density and modulus of elasticity) and color change of softwood (Norway spruce) and hardwood (beech) veneers. Compared to control, density and rigidity increased, with improved wood properties peaking after only 90 s of treatment intensity. Furthermore, the color became darker after treatment compared to control, with no signifcant color diference between treatment intensities. In conclusion, densifcation of veneers, according to the presented adapted method, provides a signifcant improvement of veneers physical and mechanical properties, and produces color changes perceptible by the human eye. Our results can be further implemented and adapted to application in industrial plants, calling for new application of densifed veneers