• Title/Summary/Keyword: no-chemical

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Enhanced performance at an early state of hydrocarbon selective catalyst reduction of NOx by atmospheric pressure plasma

  • Nguyen, Duc Ba;Heo, Il Jeong;Mok, Young Sun
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.372-379
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    • 2018
  • The improvement of $NO_x$ reduction by $Ag/{\gamma}-Al_2O_3$ with a hydrocarbon ($n-C_7H_6$) in the early state was investigated in a packed-bed dielectric barrier discharge plasma reactor. The results revealed that the combination of plasma with the catalyst enhanced $NO_x$ reduction efficiency at low operating temperatures, depending on the temperature and specific input energy. To sum up, the poor performance of the catalytic $NO_x$ reduction at low temperatures in the early stage before reaching thermochemical steady state can be greatly compensated for by using the atmospheric-pressure plasma generated in the catalyst bed.

Inhibitory mechanism of cyclohexylimminobenzoxathiol LYR-64 compound on LPS- induced NO production

  • Kim, Byung-Hak;Min, Kyung-Rak;Lee, Yong-Rok;Kim, Young-Soo
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.149.2-149.2
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    • 2003
  • Nitric oxide (NO) is known to work as an important signaling molecule involved in regulating a wide range of biological activities in the neuronal, vascular, and immune system. NO and its metabolites mediate a number of host defence functions and are also implicated in the pathogenesis of tissue damage associated with inflammation. Cyclohexylimminobenzoxathiol LYR-64 compound inhibited LPS-induced NO production in murine macrophages Raw264.7 with an IC50 value of 0.7 uM with 95.9% inhibition at 3 uM, 63.5% at 1 uM and 30.2% at 1 uM. (omitted)

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NO and $SO_2$ Removal by Dielectric Barrier Discharge-Photocatalysts Hybrid Process (유전체 장벽 방전-광촉매 복합공정에 의한 NO와 $SO_2$ 제거)

  • Kim, Dong-Joo;Nasonova, Anna;Kim, Kyo-Seon
    • 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 $SO_2$.

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Changes of Chemical Properties and Correlation under No-tillage Silt Loam Soil with Ridge Cultivation of Plastics Film Greenhouse Condition

  • Yang, Seung-Koo;Shin, Gil-Ho;Kim, Hee-Kon;Kim, Hyun-Woo;Choi, Kyung-Ju;Jung, Woo-Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.48 no.3
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    • pp.170-179
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    • 2015
  • This study was carried out to investigate the sustainable agriculture of no-tillage technique to minimize tillage problems under rain interception green house condition including recycling of the ridge and the furrow for following cultivation in Korea. Chemical properties in soils were investigated at 3-years after cultivation at conventional tillage [CT; 2-years no-tillage (2009-2010) and 1-year (2011) tillage] and no-tillage [NT; 2009-2011] field. Soil pH maintained between 5.8 and 6.0 irrespectively tillage and no-tillage. Salinity (EC), contents of total nitrogen (TN), cation exchange capacity (CEC), and exchangeable cations (K, Ca and Mg) in soil were remarkably higher in CT than in NT treatment. Salinity (EC), contents of OM, TN, CEC, and exchangeable cations in top soil and subsoil indicated higher deviation in CT than NT treatment. Organic matters and inorganic matters in soil were positive (+) correlation. Suppression of pepper growth and increase of yield were observed in no-tillage soil compared with tillage soil. These results indicated that no-tillage technique in crop culture could play an important role with respect to chemical properties in silt loam soil.

Characterization of contribution of vehicle emissions to ambient NO2 using stable isotopes (안정동위원소를 이용한 이동오염원에 의한 대기 중 NO2의 거동특성 연구)

  • Park, Kwang-Su;Kim, Hyuk;Yu, Suk-Min;Noh, Seam;Park, Yu-Mi;Seok, Kwang-Seol;Kim, Min-Seob;Yoon, Suk Hee;Kim, Young-Hee
    • Analytical Science and Technology
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    • v.32 no.1
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    • pp.17-23
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    • 2019
  • Sources of NOx are both anthropogenic (e.g. fossil fuel combustion, vehicles, and other industrial processes) and natural (e.g. lightning, biogenic soil processes, and wildfires). The nitrogen stable isotope ratio of NOx has been proposed as an indicator for NOx source partitioning, which would help identify the contributions of various NOx sources. In this study, the ${\delta}^{15}N-NO_2$ values of vehicle emissions were measured in an urban region, to understand the sources and processes that influence the isotopic composition of NOx emissions. The Ogawa passive air sampler was used to determine the isotopic composition of $NO_2$(g). In urban tunnels, the observed $NO_2$ concentration and ${\delta}^{15}N-NO_2$ values averaged $3809{\pm}2656ppbv$ and $7.7{\pm}1.8$‰, respectively. The observed ${\delta}^{15}N-NO_2$ values are associated with slight regional variations in the vehicular $NO_2$ source. Both $NO_2$ concentration and ${\delta}^{15}N-NO_2$ values were significantly higher near the expressway ($965{\pm}125ppbv$ and $5.9{\pm}1.4$‰) than at 1.1 km from the expressway ($372{\pm}96ppbv$ and $-11.5{\pm}2.9$‰), indicating a high proportion of vehicle emissions. Ambient ${\delta}^{15}N-NO_2$ values were used in a binary mixing model to estimate the percentage of the ${\delta}^{15}N-NO_2$ value contributed by vehicular NOx emissions. The calculated percentage of the ${\delta}^{15}N-NO_2$ contribution by vehicles was significantly higher close to the highway, as observed for the $NO_2$ concentration and ${\delta}^{15}N-NO_2$.