VCCI Dayori No.68

EMC on the Internet (No.7)

Coherer

Nobuhiko Tsunefuka

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  The main event of year-end and beginning of the year in the Western country is off course Christmas, but it is still the New Years celebration in Japan. There are many occasions to feel solemn including calligraphy and tea ceremony. Martial arts such as Judo, Kendo, and Aikido conduct the first training on the New Years day wishing the improvement of skills. Both art and martial arts respect the maturity of sprit in addition to good manner. Therefore, the core of the skill may be verbally passed from a master to pupil on the day that the pupil is granted a license. In this way, people in the area of art and martial arts are trying to maintain the high level of spirituality. Famous Kendo practitioner, Musashi Miyamoto, Muneyoshi and Munenori of Yagyu family, considered that the strength of mentality is very important along with advanced skills and improved the Kendo to the state of art. In his five-reel book, Gorinnosho (A book of five rings) that consists of Chinomaki (The Ground Book), Mizunomaki (The Water Book), Hinomaki (The Fire Book), Kazenomaki (The Wind Book) and Soranomaki (The Book of the void), Musashi Miyamoto has preached the importance of sprit in addition to skills. This book is read over generations not only by the people who are interested in martial arts but also by managers and educators. Gorinnosho was translated by William Scott Wilson and has become a best seller in the U.S and Europe.

•The events in the beginning of the year

http://web.kyoto-inet.or.jp/people/kyotoksd/seasons/1-saijiki.htm

http://www.mainichi.co.jp/area/kyoto/sinsyun/index.html

•Musashi Miyamoto and Gorinnosho

http://www.isis.ne.jp/mnn/senya/senya0443.html

http://www.hut.fi/~renko/gorinnosho.html

  In Japan, engineers also pay attention to mentality along with skills. Therefore, at the World Skills Competition, a great number of Japanese engineers who have strength both in sprit and skills used to participate and received many medals. However, along with the hollowing out of manufacturing sector in Japan, the number of medals kept declining. Recently, it started picking up. I hope the Japanese engineers will enjoy the good reputation again in the world due to the maturity of their skills and mentality.

•World Skills Competition

http://www.javada.or.jp/jigyou/gino/kokusai/kokusai.html

  Modern science has been remarkably progressing, however, the basic principals were discovered long time ago and they have been serving as the foundation of new discovery. Most of electric devises that are surrounding us have roots in the era of Edison and Marconi. Having series of changes, a record player that Edison invented in 1877 has been entertaining people more than 100 years. Even after the proliferation of CD players, there are many analog record funs. When people play LP records, static electricity that absorbs dust is a powerful enemy. So, there are many inventions to stop getting static electricity and a cleaner to eliminate dusts on a record. The head of HDD, one of the results of most advanced technology, is also week with static electricity. Static electricity is controlled in the production process including humidity control and static electricity elimination with much difficulty. Even how technology advances, there is something common from the past. One of the static electricity detection is coherer. The root of coherer lies in the works by Marconi.

  When Guglielmo Marchese Marconi first succeeded in communicating with wireless telegraph in 1895, he used sparking for a transmitter and coherer for a wave detector of a receiver. Coherer is a tube with nickel and aluminum powder filled in so that both ends serve as an electrode. On receiving an electromagnetic wave, insulated oxidized coating will be destroyed and coherer becomes conductive. When a de-coherence tapper hammer hits the tube, it will become nonconductive. The word, coherer, was derived from the meaning as attach and unite. Oliver Joseph Lodge found this phenomenon in 1890 and Edouard Branly innovated coherer in 1891. Some of the cases that a machine can be fixed by hitting lightly can be explained with coherer and de-coherer.

Fig. 1: Coherer

•Coherer
http://www.marconicalling.com/museum/html/objects/apparatus/objects-i=3.001-t=3-n=0.html

http://www.dia.janis.or.jp/~nasimoto/tuusin/musen.htm#m.coh

  t is widely known that the ion migration makes electrical circuits be short-circuited. Lately, it was learned that zinc whisker, zinc's whisker-like crystal, contained in dust floating in the air enters the inside of electric equipment, attaches to lead and contact of LSI and causes short circuit. GMR head for HDD that I mentioned earlier will be damaged due to the influence of discharge of low-voltage static electricity. Kagetsugu Nakayama, Research Team leader of Mesotechnology at National Institute of Advanced Industrial Science and Technology (AIST), found micro-plasma that is created by even under such low-friction conditions as writing on a pad. He has succeeded in capturing the comet-shaped images of micro-scale plasma that are observed around the contacting point of a diamond pin and a disk. This discovery is expected to develop a new path for friction energy analysis along with the conventional thermo-energy analysis.

Fig.2  Planar Image of Comet-Shaped Plasma (Courtesy of AIST)

  Entering the era of nano-technology, EMC researchers might be better to go back to the mind of physical science researchers of 19th centuries that Faraday, Maxwell and Marconi had made distinguished achievement to create new path for EMC world in the 21st centuries.

•Energy measurement of friction electricity and friction foton
http://www.mel.go.jp/soshiki/tokatsu/News-t-2000/NEWS2000-9-nakayama/NEWS2000-9-nakayama.htm

Note: Fig.2 was presented by AIST (Agency of Industrial Science and technology).

Nobuhiko Tsunefuka 1943 Born in Tokyo 1968 Graduated form Department of Engineering Science, Osaka University -1984 Worked on developing Information Technology Device at Taga Works, Hitachi, ltd. 1991- Engaged in education on EMC related matters at Hitachi Institute of Technology 1999- Planning Manager,