Vibrational properties of green wood in high-temperature water vapor
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Yoshitaka Kubojima
Abstract
The object of this study was to measure basic wood properties when water in wood is lost by heating under high temperature and high humidity. Using Sitka spruce (Picea sitchensis Carr.) specimens with dimensions of 110 mm (R)×25 mm (L)×8 mm (T), temperature and weight were measured and free-free flexural vibration tests were conducted in water vapor at 115–150°C and 75–98% relative humidity. The results were compared to those at high temperatures without humidity control under atmospheric pressure. Early in the drying process, the resonance frequency and loss tangent showed a minimum and maximum, respectively. Temporal changes in the temperature, moisture content and vibrational properties were similar to those in heating without humidity control, while the specific Young's modulus and loss tangent during the drying processes were much smaller and greater, respectively, than those in heating without humidity control. Hence, we concluded that the wood was remarkably softened by high temperature and moisture.
References
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© Walter de Gruyter Berlin New York
Articles in the same Issue
- Chemical changes in silver birch (Betula pendula Roth) wood caused by hydrogen peroxide bleaching and monitored by color measurement (CIELab) and UV-Vis, FTIR and UVRR spectroscopy
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Articles in the same Issue
- Chemical changes in silver birch (Betula pendula Roth) wood caused by hydrogen peroxide bleaching and monitored by color measurement (CIELab) and UV-Vis, FTIR and UVRR spectroscopy
- Hydrophobisation and densification of wood by different chemical treatments
- Functionalisation of wood by reaction with 3-isocyanatopropyltriethoxysilane: Grafting and hydrolysis of the triethoxysilane end groups
- Isolation and fractionation of lignosulfonates by amine extraction and ultrafiltration: A comparative study
- Bioactive phenolic substances in industrially important tree species. Part 4: Identification of two new 7-hydroxy divanillyl butyrolactol lignans in some spruce, fir, and pine species
- Characterization of physiological functions of sapwood IV: Formation and accumulation of lignans in sapwood of Cryptomeria japonica (L.f.) D. Don after felling
- X-ray scattering studies of thermally modified Scots pine (Pinus sylvestris L.)
- Differences in acoustic velocity by resonance and transit-time methods in an anisotropic laminated wood medium
- Parallel-plate rheology of latex films bonded to wood
- An assessment of the feasibility of ultrasound as a defect detector in lumber
- Vibrational properties of green wood in high-temperature water vapor
- The stiffness modulus in Norway spruce as a function of year ring
- Strain analysis in bulk forming of wood
- Decay fungi from playground wood products in service using 28S rDNA sequence analysis
- Effect of climatic variables on chromated copper arsenate (CCA) leaching during above-ground exposure
- Protic ionic liquids with organic anion as wood preservative
