Kabushiki Kaisha Toshiba

Kabushiki Kasiha Toshiba

Nobutada Aoki

Naruhiko Mukai

Yuji Sano

Chikara Konagai

Arata Ito

Muneyoshi Kikunaga

Kouki Okazaki

Kazuo Hayashi

Kenji Todori

Ikuo Watanabe

Shuji Hayase

Setsuo Suzuki

Yasushi Iseki

Etsuo Noda

Tomoko Ogawa

Hironobu Kimura

Naoki Tajima

Katsushi Nishizawa

Hideki Shimada

Kazuo Unoki

An underwater laser processing method is carried out by irradiating, through a laser beam irradiation apparatus, a laser beam having a high output, a short pulse and a visible wavelength to a surface of a structure immersed in a water to improve residual stress of a material of the surface of the structure and remove a crack or a CRUD thereof. The laser beam irradiation apparatus comprises a pulse laser device suspended into a water in which a metal material is accommodated from an upper side thereof for irradiating a laser beam having a visible wavelength to a processing position, a beam strength adjusting device for adjusting an output per 1 pulse of a laser beam generated by the pulse laser device and a mechanism for adjusting a spot diameter and a multiplexing ratio of an irradiated beam.

Underwater laser processing method and apparatus

The present invention is to clear the difficulty in determining the progress of the decomposition reaction of PCBs carried out by a conventional device for decomposing PCBs, and to provide a system for treating PCBs to render them harmless, capable of continuously determining the progress of the decomposition reaction of PCBs at real time by using a predetermined amount of a reaction solution taken out while the decomposition reaction of the PCBs is proceeding. The quantity of the polychlorobiphenyls existing in a polychlorobiphenyl-containing liquid can be determined by the system for treating polychlorobiphenyls to render them harmless according to the present invention in the following manner: a polychlorobiphenyl-containing liquid is irradiated with exciting light of from 400 nm to shorter than 450 nm, that can excite the polychlorobiphenyls, or with exciting light of from 300 nm to shorter than 400 nm, that can excite the decomposition products of the polychlorobiphenyls, and the intensity of the emitted light is measured at a wavelength between 450 nm and 600 nm, both inclusive; and the quantity of the existing polychlorobiphenyls is determined based on one of the values measured, or based on the ratio between the two values measured. The progress of the decomposition reaction of the polychlorobiphenyls can thus be determined, and the polychlorobiphenyls can be fully and sufficiently decomposed.

System, device and method for quantification of polychlorobiphenyls

A metal vapor laser apparatus has a gas supply device. The device supplies at least two kinds of gases to a container of the laser apparatus controlled individually. One of the gases is selected from the group of the molecular gas such as hydrogen gas, the other is selected from the group of rare gas such as neon gas. By adjusting the mixture ratio of these gases, the laser beam output is obtained efficiently. The molecular gas should be supplied when a metal lump, such as copper, arranged in the container is melting.

Metal vapor laser apparatus and method

Growing community of inventors

Chigasaki, Japan

Nobutada Aoki