Input and output budgets of radiocesium concerning the forest floor in the mountain forest of Fukushima released from the TEPCO's Fukushima Dai-ichi nuclear power plant accident

AbstractEstimations of radiocesium input and output concerning the forest floor within a mountain forest region have been conducted in the north and central part of the Abukuma Mountains of Fukushima, northeast Japan, after a 2–3 year period following the TEPCO Fukushima Dai-ichi nuclear power plant accident. The radiocesium input and output associated with surface washoff, throughfall, stemflow, and litterfall processes at experimental plots installed on the forest floor of evergreen Japanese cedars and deciduous Konara oaks have been monitored. Despite the high output potential in the mountainous forest of Fukushima, the results at both monitoring locations show the radiocesium input to be 4–50 times higher than the output during the summer monsoon in Fukushima. These results indicate that the radiocesium tends to be preserved in the forest ecosystem due to extremely low output ratios (0.05%–0.19%). Thus, the associated fluxes throughout the circulation process are key issues for the projecting the environmental fate of the radiocesium levels, along with the subsequent reconstruction of life emphasized within the setting

A new rotary actuator capable of rapid motion using an antagonistic cam mechanism

Animals can achieve agile behaviors such as jumping and throwing in addition to flexible behaviors with the same musculoskeletal systems, and those movements can extend the range of their activities. We have been working on actuators capable of rapid and flexible motions learning the musculoskeletal systems. In this paper, we propose a new rotary actuator using a pair of motors, springs, and cams to perform three functions, namely, normal motion, rapid or instantaneous motion, and rigidity control using an antagonistic cam mechanism, and describe the operating principle of the proposed mechanism, the mathematical model of the mechanism during rapid motion, and the design principle of the cam, which is a key mechanical element in this mechanism. Finally, we present an analysis of the error between the theoretical the measurement results during rapid motion

Development of Antagonistic High Power Joint Mechanism with Cams

Acquiring flexible and agile behaviors as seen in biological systems, the robot can achieve acrobatic movements such as jumping and throwing. These acrobatic movements are expected to extend the range of robot activity. In this research, we propose a special mechanism using a pair of motors, springs and cams, which has three functions normal operation, instantaneous operation and variable rigidity. Then, we derived a mathematical model of the mechanism and discussed the input-output characteristics of the mechanism by changing the design parameters, and analyzed the difference between the theoretical and measured results.The 2020 International Conference on Artificial Life and Robotics (ICAROB 2020), January 13-16, 2020, B-Con Plaza, Beppu, Oit

Ⅲ.Chemistry

金沢大学大学院自然科学研究科 環境科学Editor : Tazaki, Kazue |田崎, 和

The Hydrogen Burning Turn-off of RS Ophiuchi 2006

We report a coordinated multi-band photometry of the RS Oph 2006 outburst and highlight the emission line free y-band photometry that shows a mid-plateau phase at y ~ 10.2 mag from day 40 to day 75 after the discovery followed by a sharp drop of the final decline. Such mid-plateau phases are observed in other two recurrent novae, U Sco and CI Aql, and are interpreted as a bright disk irradiated by the white dwarf. We have calculated theoretical light curves based on the optically thick wind theory and have reproduced the observed light curves including the mid-plateau phase and the final sharp decline. This final decline is identified with the end of steady hydrogen shell-burning, which turned out the day ~80. This turnoff date is consistent with the end of a supersoft X-ray phase observed with Swift. Our model suggests a white dwarf mass of 1.35 \pm 0.01 M_\sun, which indicates that RS Oph is a progenitor of Type Ia supernovae. We strongly recommend the y-filter observation of novae to detect both the presence of a disk and the hydrogen burning turn-off.Comment: to appear in ApJL, 4 pages including 4 figure