The 2020 UV emitter roadmap

Solid state UV emitters have many advantages over conventional UV sources. The (Al,In,Ga)N material system is best suited to produce LEDs and laser diodes from 400 nm down to 210 nm—due to its large and tuneable direct band gap, n- and p-doping capability up to the largest bandgap material AlN and a growth and fabrication technology compatible with the current visible InGaN-based LED production. However AlGaN based UV-emitters still suffer from numerous challenges compared to their visible counterparts that become most obvious by consideration of their light output power, operation voltage and long term stability. Most of these challenges are related to the large bandgap of the materials. However, the development since the first realization of UV electroluminescence in the 1970s shows that an improvement in understanding and technology allows the performance of UV emitters to be pushed far beyond the current state. One example is the very recent realization of edge emitting laser diodes emitting in the UVC at 271.8 nm and in the UVB spectral range at 298 nm. This roadmap summarizes the current state of the art for the most important aspects of UV emitters, their challenges and provides an outlook for future developments

INVERTEBRATE FAUNA OF THE INTERTIDAL ZONE OF THE TOKARA ISLANDS -XII. FORAMINIFERA-

The foraminiferal materials here discussed are submitted to the writer by Dr. T. TOKIOKA of the Seto Marine Biological Laboratory, who visited the Tokara Islands, during the period from May 26 to June 12 of 1953, for the biological survey. As the purpose of this survey and the outline of the results obtained were already described by Dr. T. TOKIOKA (this journal, III (2), 1953), the writer wishes to give the results of identification of the submitted materials and brief notes on the species distinguished in the following. The materials treated herein are deposited in the collection of the Seto Marine Biological Laboratory

Time series analysis of the chemical and oceanographic parameters of the seawater around coral reef ecosystems, Okinawa, Japan

琉球大学21世紀プログラム「サンゴ礁島嶼系の生物多様性の総合解析」平成17年度成果発表会（平成18年3月6日開催）　会場：琉球大学大学会館3