• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.368-377
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• 2023

Natural Gas Combined Cycle(NGCC) recently receives lots of attention as an attractive form of power plants by virtue of its low carbon emission compared with coal-fired power plant. Nevertheless, it also needs carbon capture process since it is difficult to completely suppress carbon emission even for the NGCC. A simulation study has been performed to optimize operating condition of a carbon capture process using MEA considering low partial pressure of carbon dioxide in NGCC emission gas. For accurate optimization, overall process model including both NGCC and the carbon capture process has been built with a simulation software. Then, optimization in which various performance indices such as carbon dioxide absorption rate, solvent regeneration rate and power loss in the NGCC are simultaneously reflected has been done. Especially, it is noticeable that this study focuses on not only the amount of energy consumption but also the absorption and regeneration performance of carbon capture process. The best result considering all the performance indices has been achieved when the reboiler temperature is 120 ℃ and the reason has been analyzed.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.87-90
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• 1990

We compare the reflectivity spectrum and phase change of Bragg reflectors obtained by the matrix method and the coupled wave method. We show that the results obtained by the two methods agree well generally and the discrepancy between the results obtained by the two methods increases as the fractional refractive index difference between adjacent layers increases and/or the absorption loss increases, due to the approximations inherent in the coupled wave method for the analysis of multiple dielectric layers.

• Journal of KSNVE
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• v.7 no.1
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• pp.107-116
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• 1997

Friction between stone and saw of stone cutting machine generates the noise of 96-104 dB in the frequency range of 2kHz-8kHz, which may cause occupational hearing loss. By designing enclosures which are made of transparent acryl, PVC panel and absorption materials, about 15 dB noise reduction has been achieved in the stone cutting factory. It is demonstrated that this kind of enclosures can be effectively used to reduce the noise in the stone cutting factory.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.13-14
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• 2006

The use of soft-lithography instead of standard photolithography and dry etching technologies is attractive because inexpensive optical device can be realized. Polymerization using multi-photon absorption of materials is also a good method for optical waveguide fabrication. Laser induced self-writing technology of optical waveguide is also very simple and attractive. Using these processes, we can fabricate and interconnect optical circuits at once. In this presentation, several simple fabrication methods will be introduced. New optical loss evaluation method for polymer optical waveguides will also be presented

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1002-1006
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• 2000

It is diffuse sound field that measuring condition of absorption ratio and sound transmission loss for material consist of building are measured in reverberartion room and on-site. In this study, for upkeeping diffuse sound field in reverberation room, it is measured and etimated that sound field is effected according to sound source lacation and characteristics of emission directivity for sound source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.448-452
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• 2002

We report the number of calibration and test for acoustic field which were conducted in KRISS between the year of 1990 and 2001. The items contain sound level meter and calibrator for calibration and sound absorption coefficient, transmission loss, sound pressure level of siren, sound pressure level and power of acoustic instrument and relative accessories for test. The data show that the number of them have been increased continuously.

• Journal of the Korean Society of Safety
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• v.9 no.4
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• pp.119-124
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• 1994

The considerations in the noise control by enclosure are the rise of temperature and sound pressure, transmission loss, absorption coefficient of the materials, the structure of the soundproof panels, an opening and coincidence frequency. But it is very difficult that we obtain the accurate data about those in design, so, the noise reduction after enclosing does not correspond with the calculation. The difference of the noise reduction between the calculation and the measurement was 8.2dBA, and we can obtain the approximate result as the following formula which correct 10dBA, safely.

• 전기의세계
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• v.19 no.5
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• pp.8-16
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• 1970

The characteristics of dielectric absorption and dispersion in polymerized materials produced in Korea was investigated in MHz band and at several sets of temperature. For this study the theoretical basis stood on the Cole-Cole's empirical formula and it has been extended to the form convenient to investigate the observation. As the result, it has been confirmed that in most cases, two or much more sorts of dipole participate in dielectric propertics of these polymers and the materials containing aromatic molecular structure have, in general, greater loss angle than those constructed chain type molecular structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1020-1023
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• 2004

Recently, Cooling tower are used the necessary element in a residential area and living space on the viewpoint of indoor temperature control. The purpose of this study is to assistance the comfortable environment and economical measures of noise transmission mechanism on tile cooling tower. The results show that noise evaluation interact the main factor of distance reduction and diffraction reduction. Noise criterion apply to the NC level and equivalent transmission loss about already the design of noise reduction.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.454-458
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• 1995

Inhibiting action of semicarbazide, thiosemicarbazide, sym. diphenylcarbazide towards corrosion of zinc in hydrochloric acid has been investigated. The rate of corrosion depends on the nature of the inhibitor and its concentration. The values of inhibition efficiency from, weight loss, thermometric measurements are in good agreement with those obtained from polarization studies. From the polarization studies, the inhibitors used act as mixed absorption type inhibitors, increased adsorption resulting from an increase in the electron density at the reactive C=S and C=O groups and N-atoms. The thermodynamic parameters of adsorption obtained using Bockris-Swinkels adsorption isotherm reveal a strong interaction of these carbazides on zinc surface.