To investigate the accumulation and localization of heartwood extractives in Larix kaempferi (Lamb.) Carrière (Japanese larch), fluorescence microscopic observations were performed after staining with 2-aminoethyl diphenylborinate (2-APB, DPBA). First, three flavonoids ((2R, 3R)-taxifolin, (2R, 3R)-dihydrokaempferol, (2S)-naringenin) were isolated from Japanese larch heartwood. These compounds were spotted on membranes, which were subjected to fluorescence microscopic observations before and after staining with DPBA. Fluorescence spectra of the solution of these compounds were also measured. As the results, the fluorescence intensities of the flavonoids were enhanced after DPBA staining, and their intensities and color tones were characteristic for each flavonoid. After DPBA staining, fluorescence behaviors of sapwood sections were unchanged compared with the autofluorescence (before the staining), whereas the heartwood showed similar fluorescence to that of the authentic flavonoids, which was confirmed by the membrane tests. Furthermore, after extraction of Japanese larch heartwood sections by methanol, the fluorescence by DPBA staining was significantly weakened. These results indicated that fluorescence from Japanese larch heartwood sections after DPBA staining was derived predominately from the flavonoids in the sections. Consequently, it was revealed that in Japanese larch wood the distribution of heartwood extractive flavonoids could be visualized by fluorescence microscopy after DPBA staining.

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The objective of this study was to evaluate X-ray mass attenuation coefficients (MACs) for some common wood adhesives in the tube voltage range from 15kV to 100kV. Cured blocks of 10 common wood adhesives were made and their X-ray radiographs were taken with the tube voltage range of 15-100kV. The ratio of the MAC of each wood adhesive to that of wood was determined. Regarding water-based polymer-isocyanate adhesive, polychloroprene rubber adhesive, phenol-formaldehyde resin adhesive and polymethylene polyphenylene polyisocyanate adhesive, the MAC ratio varies depending on X-ray tube voltage. The variation may lead to the acquisition of adhesive-weighed radiographs suitable for observing adhesive in wood-based materials. It may also enable a dual-energy X-ray absorptiometry for determining the amount of adhesive in wood-based materials.

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Japanese Red Pine (Pinus densiflora) wood meal was subjected to pyrolysis by the use of a tube-type kiln at 350 or 600°C. Pyrolysates were separated into pyrolysis residue, condensates (liquid phase pyrolysates) which included those obtained by cooling gas phase pyrolysates to -4°C, and the remainder (gas phase pyrolysates). The weight yield of condensates varied from 30 to 50%, and that of pyrolysis residue from 20 to 50% depending on the pyrolysis temperature. In the condensates, 18 identified compounds could be identified by GC-MS (Gas Chromatography-Mass Spectrometry), and each compound was determined by GC. Detailed evaluation was made for the pyrolysis conducted by raising the temperature to 600°C. The 18 identified compounds accounted for only about 10% of the condensates. Determination of water in the condensates by ¹H-NMR suggested that 60% of the condensates was water and, thus, 40% was organic substances. Therefore, the 18 identified compounds accounted for 25% of the organic compounds in the condensates. Yield of each fraction was also evaluated based on the carbon content. Organic carbon in the pyrolysis residue and the condensates accounted for 60% and 20%, respectively, of the carbon originally present in the wood meal. Therefore, the remaining 20% was produced as gas. The carbon of the 18 identified compounds accounted for 8% of the carbon of the wood meal, and 40% of the condensate.

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We estimated the economic repercussions of using local wood products in public buildings in Kyoto. We used input-output analysis for this estimation. When the final demand for wood products was 8.132 million yen, the induced production value was 12.110 million yen, for a ratio of production value to final demand of 1.49. Next, we investigated two scenarios: The route with log and lumber production and consumption in Kyoto prefecture (Scenario 1) and the route via log and lumber production in other prefectures but consumption in Kyoto (Scenario 2). We estimated the economic repercussions for Kyoto under each scenario. For Scenario 1, this estimation indicated an induced production value of 22.021 million yen for a ratio of 2.71 per payment for the wood products. For Scenario 2, the estimation showed an induced production value of 4.560 million yen for a ratio 0.56 per payment for the wood products. It was found that under Scenario 2 economic repercussions for forestry and the wood industry were only minor.

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