scholarly journals Kibi Plateau: A stable-coherent tectonic unit in the active Japanese Islands

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takafumi Sonehara ◽  
Koshi Yagi ◽  
Hiroyuki Takeshita ◽  
Kazumasa Aoki ◽  
Shogo Aoki ◽  
...  
Author(s):  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hiroaki Eto ◽  
Chang-Kyu Rheem ◽  
Osamu Enomoto

While a type of marine turbine for tidal current generation can be chosen from several types, a vertical axis marine turbine (VAMT) should be better in Japan because sea areas around Japanese islands where current velocity is sufficient are limited. This study conducted a sea test of a VAMT of a floating type installed with six straight pitch-controllable blades. The cycloidal mechanism was adapted for the pitch control. The purpose of the study is to understand effects of ocean waves and motion of a floating body on turbine performance and behaviours of the VAMT in unideal current conditions. Besides, the data taken should be effective to consider that effects in order to design VAMTs. The setup with the setting angle of −30 degrees suggested highest performance from the sea tests, then 15% in maximum turbine power and maximum output was 40W. Ocean waves strongly affected on the turbine performance because fluid velocity changes due to ocean waves and it was unable to neglect the variation of the velocity in spite of small. The characteristics of the turbine sensitively varied because of ocean waves. The results suggested that during accelerating and decelerating incoming fluid speed, characteristics of the turbine were different in each case.


2010 ◽  
Vol 119 (6) ◽  
pp. 947-958 ◽  
Author(s):  
Junzo KASAHARA ◽  
Osam SANO ◽  
Nobuo GESHI ◽  
Yukio ISOZAKI ◽  
Shigenori MARUYAMA ◽  
...  

Radiocarbon ◽  
2002 ◽  
Vol 44 (2) ◽  
pp. 477-494 ◽  
Author(s):  
Akira Ono ◽  
Hiroyuki Sato ◽  
Takashi Tsutsumi ◽  
Yuichiro Kudo

We discuss the radiocarbon chronology of Late Pleistocene archaeology in the Japanese islands. In sum, 429 samples from more than 100 archaeological sites were compiled and then divided into three periods and four stages. The Early Upper Paleolithic, characterized by Trapezoid industries, lasted during approximately 34-26 ka. The Late Upper Paleolithic period includes both the backed-blade stage and point-tool stage, the latter appearing chronologically later than the former. This stage covers ~25–15 ka. The Final Upper Paleolithic and Incipient Jomon are distinguished by the appearance of microblade industries and the emergence of pottery at the end of this period. This period covers approximately 14-12 ka. The microblade tradition, in the broadest sense, is strongly connected to the background of peopling of the New World. New data on the transitional stage from the Middle to the Upper Paleolithic are also discussed in regards to three archaeological sites. Issues on the application of the 14C calibration to the whole Japanese Upper Paleolithic are critically evaluated.


2010 ◽  
Vol 27 (12) ◽  
pp. 939-945 ◽  
Author(s):  
Takuya Oishi ◽  
Kohji Uraguchi ◽  
Alexei V. Abramov ◽  
Ryuichi Masuda

2011 ◽  
Vol 77 (6) ◽  
pp. 975-981 ◽  
Author(s):  
Shiro Itoi ◽  
Junpei Odaka ◽  
Shunsuke Noguchi ◽  
Tsutomu Noda ◽  
Kohei Yuasa ◽  
...  

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