• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.100-109
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• 2016

In this study, the NO oxidation using dry oxidant produced by catalytic $H_2O_2$ conversion was conducted. It was shown that Mn-based $Fe_2O_3$ support catalyst has the best performance in the catalytic $H_2O_2$ conversion and its combined-NO oxidation. The reaction characteristics of NO oxidation was investigated by the various operation conditions such as $H_2O_2$ amount, oxidation temperature and space velocity. As a results, the oxidation efficiency of NO greatly depends on the oxidation reaction temperature, $H_2O_2$ amount and space velocity. The performance of NO oxidation was increased with increasing the oxidation temperature and $H_2O_2$ amount. Also, the performance of NO oxidation was decreased with increasing the space velocity.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.393-398
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• 1995

The oxo-nitrosyl complexes (n-Bu4N)2[M4O12Mo(NO)2{RC(NH2)NHO}2{RC(NH)NO}2] (M=Mo, W; R=(CH3)2CH, n-CH3CH2CH2) have been prepared by the reactions of monomeric complex containing {Mo(NO)2}2+ and polyoxometalates with isobutyl- and n-butylamidoxime. The prepared complexes were characterized by elemental analysis, infrared, 1H NMR, 13C NMR and UV-visible spectroscopy. These complexes contain two {M2O5}2+ [M=Mo, W] cores and a central {Mo(NO)2}2+ core. The {Mo(NO)2}2+ unit was the formally cis type and C2v symmetry in geometric structure. The two {M2O5}2+ cores and a central {Mo(NO)2}2+ core were not nearly interacted with electronic localization, which were identified by spectroscopy.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.283-291
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• 2003

The purpose of this research was to analyze and improve the experiment, observing the color change under compression on the equilibrium of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system, described in high school and general chemistry textbooks. Chemistry textbooks described that the reddish brown color got lighter on the compression of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system. This misinterpretation was due to no consideration of $NO_2$ concentration increase by the volume decrease. In order to propose a correct interpretation, the changes of color and temperature on compression were quantitatively measured and compared with theoretical studies. In addition, an improved experiment, excluding the effect of $NO_2$ concentration increase, was proposed to observe only the color change of the net equilibrium shift.

• Clean Technology
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• v.13 no.2
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• pp.115-121
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• 2007

In this study, we analyzed experimently the NO and $SO_2$ removal by the dielectric barrier discharge-photocatalysts hybrid process. The glass spheres were used as a dielectric material for dielectric barrier discharge and the $TiO_2$ photocatalysts were coated onto those spheres by the dip-coating method. The $TiO_2$ particles were coated in the sponge-shape, which has the larger surface area. As the voltage applied to the plasma reactor, the pulse frequency of applied voltage, or the residence time increases, the NO and $SO_2$ removal efficiencies increase. The increase in the supplied concentrations of NO and $SO_2$ leads to the higher energy for NO and $SO_2$ removal and the NO and $SO_2$ removal efficiencies decrease. These experimental results can be used as a basis to design the dielectric barrier discharge-photocatalysts hybrid process to remove NO and $SO_2$.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.152-153
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• 1999

NO$_2$는 가장 중요한 대기 오염 물질 중 하나 이다. 도시 대기 중 자동차 배출가스와 다른 연소 방출이 NO$_2$의 주원인 물질이다. 대부분 초기 NO$_{x}$은 NO로 방출되고 결국에 가서는 대기 중 오존과 반응하여 NO$_2$로 바뀐다. NO$_2$ 예측을 위해서 그리고 제어 방법을 개발하기 위해서는 NO$_{x}$ 제어 요소를 알아내는 것과 어떤 지점의 NO$_2$ 농도를 알아내는 것이 매우 중요하다.(중략)

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.107-114
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• 1995

To assess the contribution of automobile exhaust to indoor and outdoor levels of $NO_2$ around a major trunk road in Tokyo, $NO_2$ levels of 200 homes were measured at living rooms, kitchens and outdoor at each season, from the summer of 1990 to the spring of 1991, $NO_2$ level was measured for four days using diffusion $NO_2$ dosimeter. Outdoor $NO_2$ levels at each season and indoor $NO_2$ levels at seasons when heaters were not used decreased according to the distance from the roadside. The differences between $NO_2$ levels at zone I(within 20m from the roadside) and zone III(beyond 50m) was about 3 ppb. Automobile exhaust seemed to contribute to this difference. At seasons when heaters were used, indoor $NO_2$ levels of the homes equipped with vented heater, decreased according to the distance from the roadside. However, there was no correlation between indoor levels and the distance from the roadside at homes equipped with unvented heater.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.330-336
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• 2005

The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.3-14
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• 2008

ASM No. 2(Activated sludge model No. 2) is very useful model to analyze the wastewater treatment which removes nitrogen and phosphorus. But, it is difficult to apply ASM No. 2 to control of wastewater treatment since it has 17 material divisions and 46 parameters. So the purpose of this study was the simplification of ASM No. 2 and the provement of simplification model. Firstly ASM No. 2 was simplified with 5 material division and three phases(Anaerobic, aerobic, anoxic phases). The simplified model was proved by R-square using track study data. As a result of provement, the values of R-square in ${NH_4}^+$ were 0.9815 in ASM No. 2 and 0.9250 in simplified model and in ${NO_3}^-$ were 0.8679 in ASM No. 2 and 0.7914 in simplified model and in ${PO_4}^{3-}$ are 0.9745 in ASM No. 2 and 0.9187 in the simplified model when the ability to express the material variation was compared by R-square. So, the simplified model has enough ability to express the variation of ${NH_4}^+$, ${NO_3}^-$ and ${PO_4}^{3-}$.

• International Journal of Automotive Technology
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• v.2 no.2
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• pp.77-83
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• 2001

Effect of ethene on the $DeNO_X$ conversion process in a simulated diesel engine operating conditions was investigated experimentally and theoretically. With the addition of even a small amount of ethene the NO to $NO_2$ conversion enhances greatly. The energy required to convert one NO molecule is 27 eV with 250 ppm ethene added, while 137 eV without ethene at 473 K. The effect of energy density, temperature, and the initial concentrations of ethene and oxygen are also discussed and the results show that the increase of the mentioned parameters lead to the promotion of NO oxidation. A kinetic model used in this study shows good agreement with the experimental result. Byproducts like formaldehyde ($CH_2$ 0) and methyl nitrite ($CH_3$ ONO) predicted by model calculation are broken up into CO and $H_2O$ eventually when high energy is delivered to the gas mixture. Sensitivity analysis shows that the main reactions of NO oxidation when ethene is added we: $HO_2+ NO \arrow NO_2 + OH, RO_2 + NO \arrow NO_2 + RO$, where R is a hydrocarbon radical. Also the direct oxidizing reaction of NO with O cannot be neglected.

• Journal of Pharmaceutical Investigation
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• v.5 no.2
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• pp.57-62
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• 1975

It was many differances to evaluate of the effect of excipients on colour fading in FD & C Yellow No.5 by use Tintometer and nearly is not effective in FD & C Red No. 2. When we observed colour fading in suger coating formulations by tintometer, FD & C Red No.2 was appeared to follow zero order reaction and FD & C Yellow No. 5 was not follow zero order reaction or first order reaction. Also, we could know the tendency of colour fading by visible spectrum, but it was net suitable method for this experiment more than by tintometer. The relative colour fading effect of the surfactants(Polysorbate) was as follows: Tween 60> Tween 80> Tween 20. In addition to, Benzalkonium chloride was reacted with FD & C Yellow No.5, so the stronger colour was appeared. On the other hand, the weaker colour was appeared in FD & C Red No.2. While, the sunscreening agents was not almost effective in colour fading of FD & Yellow No. 5 and FD & C Red No. 2.