Yoshioka T.,NihonUniversity |
Sugiura K.,NihonUniversity |
Croatian Journal of Forest Engineering | Year: 2012
An experiment on the growing and harvesting of willow trees aimed at short rotation forestry was conducted in northern Japan. Willows were harvested using a sugarcane harvester from southern Japan during its agricultural off-season. The growing experiment showed the high potential of willow plantations to produce woody biomass of more than 10 dry-t/ha/y. The harvesting experiment showed that space for turning around, one line in one row as a planting method, a growing cycle of three years, and an extractor fan in the harvester are necessary for mechanical harvesting. Mechanical harvesting was considered to have little influence on willow regeneration provided that the machine cut reasonably well-grown trees. The system performance of harvesting and collecting willow billets in a hypothetical model field was calculated as 22.4 m3/h, suggesting the feasibility of supplying low-cost wood chips.
Ishimaru S.,I2S2 Co. |
Hata I.,Nihon University |
Mikami J.,NihonUniversity |
Kimiduka M.,I2S2 Co.
Journal of Structural and Construction Engineering | Year: 2010
This paper presents a simple design method for tuned dynamic mass systems (T.D.M.S.) consisted of dynamic mass-viscous damper-spring devices. The systems are designed by the law of geometric mean as a tuning rule, which is derived from the properties of the invariant point theory. The paper indicates that performance of the structure basically depends on the auxiliary stiffness factor which is the ratio of the stiffness of the devices to that of the main structure. And it also shows that the structures with T.D.M.S. can easily hold viscous damping factors more than 0.20 for the 1s t and 2 n d modes, when the auxiliary stiffness factor is controlled more than 0.25.