A new approach is proposed for the evaluation of the brittleness of heat-treated Styrax tonkinensis wood. Heat treatment made wood more brittle when wood was heated at a higher temperature or for a longer time. The brittleness increased to four times that of the control when wood was heated at 200°C for 12 h. For treatment at 160°C, the increase in brittleness without any change in weight is thought to be possibly caused by the relocation of lignin molecules. At higher temperatures, loss of amorphous polysaccharides due to degradation is thought to become the main factor affecting brittleness. The crystallites that were newly formed after 2 h of treatment showed brittleness that was different from that of the inherent crystallites remaining after 12 h of heat treatment. This inherent crystalline cellulose possibly plays a role in brittleness. There is also the possibility of using color to predict the brittleness of heat-treated wood.

It is found that epitaxial CeO2 layers with (100) or (110) orientation can be selectively grown on Si(100) substrates by controlling substrate bias in reactive dc magnetron sputtering. Adopting a two step growth method; ultrathin metallic Ce layer deposition at room temperature followed by a silicidation process at 800 °C, and subsequent reactive sputtering in an Ar/O2 mixture environment, the CeO2(100) layer is grown on practical Si(100) surfaces prepared by the usual wet cleaning method.

No abstract

A new approach based on hydrogen-deuterium exchange is proposed for measuring accessible OH groups in wood. The deuterium (D) exchanged for hydrogen in OH groups in wood was converted to D2O by combustion in oxygen gas then diluted in deionized water, and subsequently determined by 2H NMR spectroscopy. The amount of accessible OH groups in Styrax tonkinensis wood is approximately 6.8 mmol g-1. This measurement is very accurate, with an error of approximately 0.2 mmol g-1. Heat-treated wood has a lower amount of accessible OH groups than non-treated wood. This finding is in agreement with the decreased hygroscopicity of heat-treated wood and explains, at least partially, its increased fungal resistance.

No abstract