Yasuhiko Arakawa Yasuhiko Arakawa Yasuhiko Arakawa (Japanese , "Arakawa Yasuhiko"; born 6 November 1952) is a Japanese physicist. His research focuses on semiconductor physics, including growth of nanostructures and their optoelectronic applications. Among his main achievements are the proposal of the concept of quantum dots and their application to quantum dot lasers, the observation of exciton-polariton Rabi-splitting in a semiconductor microcavity, or, recently, the first 3D photonic crystal nanocavity lasers with quantum dot gain. Yasuhiko Arakawa received a B.S. degree in 1975 and a Ph.D. degree in 1980, respectively, from the University of Tokyo, both in Electronics Engineering. In 1981 he became
Sumida M.2593 Sumida M.2593 The Sumida M.2593 (Type 91) was an armoured car produced in Japan in the 1930s. It could operate on both the roadway and railway lines. Designed by the Sumida firm, the M.2593 was produced beginning in 1933 at the Ishikawajima Motor Works. A defining feature of this vehicle is that its six road wheels could be exchanged for flanged railway wheels. When not in use, the tires would be secured to the sides of the hull. The vehicle had four built-in jacks for use when the wheels were changed. It would take ten to twenty minutes to change