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Volume 34, Issue 4
Displaying 1-7 of 7 articles from this issue
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Shigeru YAMAGUCHI2006 Volume 34 Issue 4 Pages 274
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (172K) -
Frank K. TITTEL, Yury BAKHIRKIN, Anatoliy A. KOSTEREV, Gerard WYSOCKI2006 Volume 34 Issue 4 Pages 275-282
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThere is an increasing need in many chemical sensing applications ranging from environmental science to industrial process control as well as medical diagnostics for fast, sensitive, and selective trace gas detection based on laser spectroscopy. The recent availability of novel pulsed and continuous wave (cw) quantum and interband cascade distributed feedback (QC and IC DFB) lasers as mid-infrared spectroscopic sources addresses this need. A number of spectroscopic techniques have been demonstrated worldwide. For example, the authors have employed infrared DFB QC and IC lasers for the detection and quantification of trace gases and isotopic species in ambient air at ppmv, ppbv and even sub-ppbv levels by means of direct absorption, cavity enhanced, photoacoustic and wavelength modulation spectroscopy.View full abstractDownload PDF (1778K) -
Shun-ichi HAYASHI, Tetsuya SUZUKI, Shun-ichi ISHIUCHI, Masaaki FUJII2006 Volume 34 Issue 4 Pages 283-288
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSFor monitoring of hazardous organic compounds, we have been developing an on-line analytical instrument based on a supersonic jet resonance enhanced multi-photon ionization (Jet-REMPI) mass spectrometry. We have attempted to apply this technique to monitor transient attitudes of hazardous organic compounds in the exhaust gas. It has become possible that the real time monitoring of the gaseous compounds in the atmosphere by our instrument with a continuous sample introduction. We demonstrated that the signals of monochlorobenzene in the chimney could be detected. And the delay time between the gas emission and the gas detection through the 23 m long stainless steel pipe kept 200 °C was 150 seconds. It has been proved that the molecules monitored were well cooled as the result of REMPI spectra. It is greatly advantageous for the selective detection of a specific molecular species.View full abstractDownload PDF (1169K) -
Masahiro KAWASAKI, Shin-ichi ENAMI2006 Volume 34 Issue 4 Pages 289-294
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA new photoabsorption technique for measuring the spectra of trace amounts of species with both high sensitivity and high spectral resolution is described. The method is based on measurement of the time rate of decay of a pulse of light trapped in a high reflectance optical cavity. In this review paper, we present an account of the basic theory, development, and applications of this method to samples in the gas, liquid and solid phases. In addition to a general review, experimental data are presented that demonstrate the simplicity, sensitivity, and generality of this powerful spectroscopic tool.View full abstractDownload PDF (1087K) -
Yoshizumi KAJII, Jun MATSUMOTO2006 Volume 34 Issue 4 Pages 295-299
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe developed the instrument to measure ambient NOx concentrations in ppt level by laser induced fluorescence technique. Diode laser pumped solid state (DPSS) laser was used as the excitation source for NO2 molecules its self and dye laser for NO3 detection. We employed FAGE (fluorescence assay of gas expansion) technique to detect both NO2 and NO3 radicals. We achieved the ultra high sensitive NO2 analyzer whoes LOD (limit of detection) was 1.8 ppt. We brought the instrument to the Rishiri island Hokkaido and tested the utility and found the high potential for the practical use. We also developed NO3 sensor as an extension of NO2 analyzer. We employed tunable dye laser as the excitation source for NO3 molecule at 623 nm band. Successfully we applied NO3 analyzer to detect N205 at the campus of Tokyo Metropolitan University in March 2004 because N205 was easily thermally decomposed into NO3 and NO2.View full abstractDownload PDF (973K) -
Hideki NINOMIYA, Saeko YAESHIMA, Tetsuo FUKUCHI2006 Volume 34 Issue 4 Pages 300-304
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSMeasurement of flue gas constituents in fossil fuel-burning power plants is necessary for prevention of corrosion damage to plant machinery and for environmental protection. Optical measurement techniques for continuous monitoring of NOx and SO2 have been well-estabilished, but monitoring of SO3 still relies on sampling and chemical analysis. Since SO3 forms sulfuric acid upon reaction with water vapor and causes corrosion damage, its continuous, real-time monitoring is of importance. This paper provides a review of optical SO3 measurement techniques, and presents some experimental results on spectrally resolved measurement of SO2 and SO3 using Raman scattering.View full abstractDownload PDF (864K) -
Tetsuya TANIYAMA, Tomoyuki OZAKI, Toshiya KOMURO2006 Volume 34 Issue 4 Pages 305-310
Published: April 15, 2006
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThis paper describes a method of welding two plates of glass together using a CO2 laser with a laser power of 15.2 W and a wavelength of 10.6×10-6m. The experiment is conducted using plates of borosilicate glass and borosilicate kron glass (BK7). The thicknesses of glass plates are 1.0×10-3m. The glass plates are preheated at above 400°C in an electric furnace and then exposed to a laser beam of a power density of 7.34×106 W/m2 with a welding speed of 0.6 ×10-3 m/s. The welding is successful for a number of trials without failure. The welding of cover glasses with a thickness of 0.12×10-3m is also successfully carried out.View full abstractDownload PDF (3381K)
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