Tomoo Nagahama

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Insertion of a thin nonmagnetic copper Cu(001) layer between the tunnel barrier and the ferromagnetic electrode of a magnetic tunnel junction is shown to result in the oscillation of the tunnel magnetoresistance as a function of the Cu layer thickness. The effect is interpreted in terms of the formation of spin-polarized resonant tunneling. The amplitude of(More)
and Ken'ichi Tatematsu for their useful discussions, comments, and advice. I also thank anonymous referee of the Astrophysical Journal for the recommendation on discussion on the eects of extinction. Also I thank all my friends and parents for helping and encouraging me in various aspects throughout this work. ABSTRACT Stars have been studied for a long(More)
A high voltage source generating the fast rising square wave voltage has been developed for a high efficiency ozone generator. The voltage source incorporated a rotating spark gap switch. Lifetime of the voltage source is determined by erosion of the spark gap switch. In order to obtain a long life time, various electrode materials have been experimentally(More)
In order to store fresh fruits or vegetables, exhaled ethylene gas should be removed. Pulsed streamer corona discharge has been applied for this purpose. Ethylene of 20 ppm concentration diluted in the air can be effectively removed with more than 99.5% efficiency with a treatment period of 0.3 s. It was experimentally confirmed that the energy efficiency(More)
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