Using a test tool with sharp cutting edge, tool angle 30° and clearance angle 0°, the effect of the undeformed chip thickness on the cutting performance in modeled veneer cutting of sugi was investigated. The experimental conditions of nominal chip thickness were 0.13, 0.26, 0.45, 0.72, and 0.89 mm. The purpose of this study was to obtain the minimum chip thickness which could form the chip. The veneer cutting process consisted of cutting (1) with chip thickness of 0 to nominal chip thickness, cutting (2) with constant nominal chip thickness, cutting (3) with nominal chip thickness to chip thickness 0 and burnishing (4) with chip thickness 0. The cutting force, machined surface profile, tool feed and rotational angle of the work pieces were measured in all cutting processes. Changes of cutting force, frictional angle on the face, frictional angle on the back and cutting error were analyzed. In cutting (1) and cutting (3), no chip was produced with the undeformed chip thickness when the frictional angle was larger than 90°. The undeformed chip thickness at the frictional angle of 90° was the minimum chip thickness. In this experimental condition, the minimum chip thickness was about 0.2 mm regardless of nominal chip thickness. The burnishing force caused by the cutting tool pushed the remaining volume that could not be cut with chip thickness less than the minimum chip thickness.

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To efficiently convert wood biomass to bio-oil and carbonized wood, a novel fast pyrolysis reactor was developed using a direct pulsed current-heating method. Interestingly, an electrical microdischarge phenomenon between the wood-biomass particles in the direct heating system of the new reactor can be expected, which has never previously been reported in a conventional indirect heating system. The direct pulsed current was conducted through a titanium pipe measuring 125 to 250μm at 400 to 550°C and a throughput of 50 g/h pulverized wood biomass to obtain pyrolysis products. Bio-oil yield was 40% when heated at 450°C, and the bio-oil had a higher heating value of 16 MJ/kg. Transmission electron microscopy observations revealed the formation of porous nanocarbons, with graphitic structure in the carbonized wood, on the anode when heated at 500°C.

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Using vertically and radially cut samples from a 25-year-old Elaeis guineensis (oil palm) trunk, we determined levels of alcohol-benzene extract, holocellulose, lignin, hot water extract and hot water extractable glucose. The results showed that the higher and further inside the oil palm trunk the sample was located, the more hot water extract was observed, and the more hot water extractable glucose was obtained. The hot water extractable glucose, fructose and sucrose contents of the sample oil palm trunk, in the section from between 0.5 to 9.5 m of the tree's height, were estimated as 63, 13 and 11 kg, respectively. The estimated ethanol content of this oil palm trunk section was 51.5 L, and estimated ethanol production per cultivated area was 7.4 kL/ha. The ethanol yields from fermentation of the sugar liquors from oil palm wood meals using the fermentative bacterium Zymomonas mobilis were almost the same as those from a glucose solution. Thus it would appear that there was no fermentation inhibitor in oil palm wood meal. The present examination indicated that waste oil palm trunks could provide material suitable for bio-ethanol production.

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The ratio of working stress to allowable stress on columns and sill plates in three wooden houses, which were build in a heavy snow area, was investigated. Calculated stresses for columns and sill plates are buckling stress and compression stress perpendicular to the grain, respectively. The results of the investigation suggest that the load-bearing ratio (working stress/allowable stress) on columns and sill plates at each combination of load and duration was significantly low except some cases. The results also clarified that for long term load (dead and live loads) and long term load from snow, those columns and sill plates which support a longer beam for a large space, have relatively lower safety margins, and for short term load (seismic and wind loads), those columns and sill plates which compose a stronger shear wall, have relatively lower safety margins.

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To clarify the causes of fermentation inhibition during ball-vibration simultaneous saccharification and fermentation (BVSSF) used for conversion of spent maitake (Grifola frondosa) culture medium to ethanol, we investigated the effects of various factors on BVSSF in detail. The BVSSF was carried out by shaking a plastic bottle containing stored maitake culture medium, cellulase, yeast and various sizes of zirconia balls. The effects of zirconia ball size (diameter of 1, 3, 5 or 10 mm) and shaking speed (100 or 200 rpm) on ethanol conversion during BVSSF were analyzed. The results indicated that physical stress may affect ethanol production ability of yeast.

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