• 한국결정성장학회지
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• 제15권3호
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• pp.114-119
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• 2005

This study has been carried out with the eight HPHT processed NOUV diamonds - two yellow, two yellowish green, two green and two orangy yellow color stones. The gemological properties of these diamonds included a highly saturated body color, graphitized fractures around the girdles, tension cracks around crystalline inclusions, long-wave UV with medium yellowish green to a very strong yellowish green luminescence, and short-wave UV with faint yellowish green to a strong yellowish green luminescence. Distinctive features of spectroscopic properties include absorption peaks at 415 nm and 503 nm a strong absorption band at $460{\sim}480nm$ and a H2 center at 986nm. Infrared spectra showed an absorption peak at $1344cm^{-1}$ (C center), which is the characteristics related to single substitutional nitrogen.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1665-1667
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• 2003

Recently, a breaking capacity increases with breaking method using gas pressure from ablation materials in low voltage circuit breakers. In this paper, we investigated arc quenching materials with spectroscopic method. Especially, Hydrogen spectrum was investigated because its dielectric characteristics are better than other gases. We selected two arc quenching materials, UP and PA6, that use in circuit breakers. They had hydrogen spectrums, but PA6 was better than UP in the qualitative aspect.

• Journal of Astronomy and Space Sciences
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• 제19권4호
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• pp.319-326
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• 2002

인공위성의 본체 및 탑재체 제작에 사용되고 있는 구성품 재질 12점을 수집하여 가시광 영역에서 지상 분광실험을 수행한 결과 위성체 구성품 재질별로 분광반사율과 분광유형이 뚜렷이 차이를 보였고 위성체의 재질별 분류 및 식별이 가능하였다. 인공위성 재질의 지상 분광실험 결과는 운용초기에 있는 인공위성이나 우주잔해물을 실제로 분광관측하여 얻은 자료와 비교함으로써 대상물의 재질유형 및 재질구성비, 그리고 크기와 중량을 예측하는데 활용될 수 있을 것이다.

• Journal of the Optical Society of Korea
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• 제8권4호
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• pp.156-162
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• 2004

The spectroscopic model is proposed to analyze the gain bandwidth of a fiber Raman amplifier (FRA) with a multiple wavelength pumping scheme based on Raman gain theory. The oscillatory lineshape, which is the analytic function to analyze Raman gain spectra, allows us to estimate the gain bandwidth of the FRA. Based on the proposed theoretical modeling, we design and analyze the characteristics of the FRA using the combined multiwavelength pumping sources. We achieved the extended gain bandwidth of the FRA over 80 nm with the small gain ripple less than 0.5 dB. Threshold pumping power and effective noise figure for the FRA can be also analyzed by using the proposed model, which is also applicable for versatile fibers with other doping materials. The proposed analysis method can be useful for the design of FRA with the multiwavelength pumping scheme.

• 한국레이저가공학회지
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• 제5권2호
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• pp.17-22
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• 2002

Characteristics of micro carbon structures fabricated with laser-induced chemical vapor deposition (LCVD) are investigated. An argon ion laser (λ＝514.5nm) and ethylene gas were utilized as the energy source and precursor, respectively. The laser beam was focused onto a graphite substrate to produce carbon deposit through thermal decomposition of the precursor. Average growth rate of a carbon rod increased for increasing laser power and pressure. Micro carbon rods with good surface quality were obtained at near the threshold condition. Micro carbon rods with aspect ratio of about 100 and micro tubular structures were fabricated to demonstrate the possible application of this method to the fabrication of three-dimensional microstructures. Laser Raman spectroscopic analysis of the micro carbon structures revealed that the carbon rods are consisting of amorphous carbon.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.72-78
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• 1993

The application of time-resolved laser induced fluorescence spectroscopy (TRLIF) to the complexation studies of Eu(III) and Cm(III) with humic substances is described. Using this method, three different spectroscopic characteristics(excitation spectra, emission spectra, and lifetimes) of these aquo ions and their complexes can be directly measured. By observing shifts in the wavelength and changes in the lifetime and intensities of the fluorescence emission, the information on the complexation behavior of humic substances with these trivalent metal cations in an aqueous solution, as well as energy transfer mechanisms, can be obtained. In addition, this method allows precise spectroscopic quantification of the complexation processes at very low concentrations of both components.

• Journal of Advanced Marine Engineering and Technology
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• 제23권3호
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• pp.360-368
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• 1999

The paper describes spectroscopic characteristics of plasma induced in the pulsed YAG laser welding of alloys containing a large amount of volatile elements. The authors have conducted the spectroscopic analyses of laser induced Al-Mg alloys plasma in the air and argon atmosphere. In the air environment the identified spectra were atomic lines of Al, Mg, Cr, Mn, Cu, Fe and Zn and singly ionized Mg lines as well as the intense molecular spectra of ALO and MgO formed by chemi-cal reactions of evaporated Al and Mg atoms from the pool surface with oxygen in the air. In argon atmosphere MgO and AlO spectra vanished but AlH spectrum was detected. the hydrogen source was presumable hydrogen dissolved in the base metals water absorbed on the surface oxide layer or $H_2$ and $H_2O$ in the shielding gas. The resonant lines of Al and Mg were strongly self-absorbed in particular self-absorption of the Mg line was predominant. These results show that the laser induced plasma was made of metallic vapor with relatively low temperature and high density.

• 생태와환경
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• 제56권4호
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• pp.339-347
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• 2023

본 연구는 TOC/TN-IRMS를 이용하여 총 유기탄소 및 총 질소 안정동위원소 분석법을 연구하였으며, 수환경 중저농도 시료에서도 분석이 가능하게 시스템을 구축하였다. 수생태계로 유입되는 다양한 유기탄소 기원을 파악하기 위하여 형광지표와 δ¹³C-DOC 안정동위원소비를 활용한다면 효율적인 수질 관리를 위한 해석기능을 제공할 것이며, 추후 유역 오염원의 대표값(end member)의 지속적인 조사를 통하여 자료구축이 이루어져야 할 것이다.

• 천문학회지
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• 제29권spc1호
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• pp.333-335
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• 1996

Here we report the results from spectroscopic observations of soloar active regions in the HeI 10830 ${\AA}$ line at the German Vacuum Tower Telescope(VTT) in Tenerife during the August 199:3 International EFR(Emerging Flux Region) Campaign. Four active regions in various stages of their evolution, i.e., NOAA7558, 7560, 7561, and 7562, were ovserved on 10 August 1993. From the observed HeI 10830 ${\AA}$ spectra in these active regions, spectroscopic quantities such as equivalent width(EW), doppler shift, doppler width, etc., were derived(see Figure l(a)) and the correlation between them were studied(see Figure l(b)). Our main results are as follows: (I)In NOAA7562, which is a young and evolving EFR, the EW is large, while it is small around a simple and roundish spot of NOAA7558. (2)In these active regions, redshift in the 10830 line is dominant when the EW is larger. (3)As the doppler width increases, the line tends to shift redward. (4)When the EW is smaller, it seems to exist another component which have dynamic characteristics different from the redshifting component. In NOAA7560 and NOAA7561, regions which have several small spots, the values of the EW are intermediate. Results (2) and (3) may suggest the possible existence of downflow above active regions, if the HeI 10830 ${\AA}$line is formed in the upper chromopshere, and it is consistent with the earlyer result from the SMM extreme-ultraviolet observation by Klimchuk(1987, Astrophys. J., 323, 368) (to be submitted. to Astronomy and Astrophysics; an extended abstract)

• 한국광학회지
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• 제6권4호
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• pp.259-265
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• 1995

국내 민수용으로 유통되고 있는 20여종의 무반사 안경렌즈들을 선정하여 광학적 특성을 분석하였다. 분광광도계를 사용하여 측정한 반사특성과 투과특성을 렌즈의 굴절력, 각 무반사층들 및 렌즈기층에 의한 영향과 연결시켜 분석하였다. 흡수단 근방에서의 겉보기 흡수스펙트럼은 기층물질에 따라 결정되며 400-700nm의 파장대역에서 대부분의 시료들의 겉보기 흡수스펙트럼과 반사스펙트럼은 강한 양의 상관관계를 보여준다. 예외적으로 기층에 의한 흡수가 큰 렌즈들은 상관관계가 약해지며 이와 같은 기층에 의한 흡수는 무반사 특성에 부정적인 효과를 가진다. 또한 국내에서 제작되는 $SiO_2/TiO_2/SiO_2/ZrO_2/Cr$ 다층박막층을 c-Si 기층위에 성장시키면서 각 단계별로 ex-situ 분광타원해석법으로 분석하여 $TiO_2$ 박막과 $ZrO_2$ 박막의 조밀도가 80% 정도에 불과하며 박막이 두꺼원 짐에 따라 박막에 수직한 방향으로 균일하지 않음을 확인하였다. 마지막으로 실시간, in-suti 측정을 바탕으로하여 엄밀한 사양이 요구되는 다층박막, 초격자박막 등을 재현성있게 성장시킬 수 있는 가능성에 대해 토의하였다.