• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.250-253
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• 2009

Effective methods for monitoring the quality of polycrystalline silicon (poly-Si) films are discussed. Raman spectroscopy is typically used to determine crystallinity of poly-Si, but this method has limitations for data gathering on large substrates for mass production of poly-Si TFT backplanes. Spectroscopic ellipsometry is proposed as an alternative for fast and simple estimation of poly-Si quality on large substrates. By using both ellipsometry and Raman spectroscopy, it is possible to determine whether the quality and uniformity of the poly-Si films meet the criteria required for mass production of TFT backplanes for AMOLED panels.

• Journal of the Korean institute of surface engineering
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• v.53 no.5
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• pp.265-270
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• 2020

We investigated mechanochemical radical, which is concomitant with chemical lift-off lithography(CLL), on the self-assembled monolayer(SAM)/electrodes and a polydimethylsiloxane(PDMS) using a colorimetric and a spectroscopic method. The 11-mercaptoundecanol(MUO)/Au or the 11-hydroxyundecylphosphonic acid (HUPA)/ITO were contacted with bare or activated PDMS. After contact, the each of SAM/substrates and the PDMS were immersed in a 2,2 Diphenyl-1-picrylhydrazyl(DPPH) radical scavenger. The color of the DPPH exposed to the PDMS was changed from purple to yellow and the absorbance decreased definitely at 515 nm wavelength. The SAM/substrates, however, have caused small changes in spectroscopic property, indicating no existence of radical species. We concluded that mechanochemical radicals were formed by homolytic cleavage of PDMS molecules upon external force and hardly transferred on the SAM/substrates.

• Journal of the Optical Society of Korea
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• v.8 no.4
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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.

• Laser Solutions
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• v.5 no.2
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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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• v.2 no.3
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• pp.105-112
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• 1981

Various $3{\alpha}$, $5{\alpha}$-cyclocholestan-6${\beta}-yl$ ethers were synthesized from solvolysis reactions of cholesteryl tosylate. ${3\alpha}$, $5{\alpha}$-Cyclocholestan-6${\beta}-yl$ sulfides were the sole products when cholesteryl tosylate was solvolyzed in thiol solvents. Diol solvolysis products were derivatized to aromatic esters, and nuclear magnetic resonance spectroscopic method was used to show that aromatic rings can approach C-18 methyl group and the side chain.

• Advances in nano research
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• v.13 no.5
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• pp.437-451
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• 2022

Synthesis approaches usually affect the physical and chemical properties of ferrites. This helps ferrite materials to design them for desired applications. Some of these methods are mechanical milling, ultrasonic method, micro-emulsion, co-precipitation, thermal decomposition, hydrothermal, microwave-assisted, sol-gel, etc. These methods are extensively reviewed by taking example of ZnFe₂O₄. These methods also affect the microstructure and local structure of ferrite which ultimately affect the physical and chemical properties of ferrites. Various spectroscopic techniques such as Raman spectroscopy, Fourier Transform Infrared spectroscopy, Ultra Violet-Visible spectroscopy, Mossbauer spectroscopy, extended x-ray absorption fine structure, and electron paramagnetic resonance are found helpful to reveal this information. Hence, the basic principle and the usefulness of these techniques to find out appropriate information in ZnFe₂O₄ nanoparticles is elaborated in this review.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.77-81
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• 1981

A flew spectroscopic method was developed to determine microquantities of nicotine with cyanogen chloride and pyrazolon. Absorption maximum of tile derivative solution appeared at 520nm. The color formed in the proposed method was stable for at least 30 min. at pH 7.5, and followed the Lambert-Beer's law between tile limits of 1 and 5 micrograms of nicotine. The relative errors in burley and flue-cured tobacco leaves were $\pm5%$ in comparison with the Griffith method.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2006.11a
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• pp.213-215
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• 2006

• Journal of Pharmaceutical Investigation
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• v.6 no.3
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• pp.10-13
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• 1976

Trace Element in Deer Horn have been determined Ca, Mg, Fe, Zn, Mn, Al, As, Co and as were detected by partition paper chromatography and spectroscopic method.

• The Korean Journal of Applied Statistics
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• v.10 no.2
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• pp.227-239
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• 1997

PLSR is a powerful multivariate statistical tool that has been successfully applied to the quantitative analyses of data in spectroscopy, chemistry, and industrial process control. Data in spectorscopy is represented by spectrum matrix measured in many wavelengths. Problems of many kinds of noise in data and itercorrelation between wavelengths are quite common in such data. PLSR utilizes whole data set measured in many wavelengths to the analysis, and handles such problems through data compression method. We investigated the PLSR theory, and applied this method to the data for spectroscopic diagnosis of Total Hemoglobin in whole blood.