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A Study on the Formation of Nitrate in Atmosphere(II) (환경 대기중에서 Nitrate의 생성에 관한 연구(II))

  • 천만영;이영재;김희강
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.3
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    • pp.216-221
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    • 1993
  • This study was carried out to determine the concentration of gaseous nitrate$(HNO_3)$ particulate nitrate$(NO_3^-)$ and conversion rate of NOx to nitrate in atmosphere in Seoul from Oct 1991 to July 1992. The average concentration of gaseous nitrate in daytime(09:00 - 17:00) was 9.93, 3.37, 7.40 and 10.40$\mug/m^3$ and, in highttime was 6.21, 7.31, 4.79 and 3.86$\mug/m^3$ respectively. The concentratin of $HNO_3$ was greater in summer and daytime than winter and nighttime. But the concentration of $NO_3^-$ was greater in winter and nighttime than in summer and daytime. The average conversion rate of NOx to $HNO_3$(Fn) indaytime was 13.18, 3.78, 9.13 and 23.13% and, in nighttime was 3.06, 1.37, 1.70 and 8.72% during fall, winter, spring and summer respectively. But the average conversion rate of NOx to $NO_3^-$(Fn') in daytime was 5.79, 5.77, 2.63 and 3.90% and in nighttime was 5.95, 6.51, 3.25 and 4.84% respectively. The average conversion rate of NOx to total nitrate $(HNO_3 + NO_3^-)$(Fn') was 12.72, 7.81, 7.82 and 18.40% respectively. The average conversion rate of NOx to $HNO_3$(Fn) was greater than $NO_3^-$(Fn') about 1.6 times.

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Numerical Simulation on Ventilation Characteristics of an Underground Bus Parking Lot (버스전용 지하주차장의 환기 특성에 관한 수치해석적 연구)

  • Seung, Sam-Sun;Lee, Seung-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.2
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    • pp.179-184
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    • 2007
  • In this paper, the ventilation characteristics of an underground parking lot with 17 buses has been investigated for two cases by computational fluid dynamics. It has been found that the average concentration of CO and $NO_x$ gas in the parking lot were 1.3 and 0.3 ppm respectively, when four buses operated. When the fifteen vehicles stopped in the parking lot, the average concentration of CO and $NO_x$ gas was 2.9 and 0.8 ppm respectively. The average concentration of two pollutants$(CO,\;NO_x)$ are lower than the standard values. Therefore the facilities and its location is proper to ventilation.

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Analysis of Air Pollution Concentrations at Cheju Baseline Measurement Station (제주도 고산 측정소에서의 대기오염 배경농도 측정 및 분석)

  • 박경윤;이호근;서명석;장광미;강창희;허철구;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.4
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    • pp.252-259
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    • 1994
  • A ground station has been established at Kosan, Cheju Island, since January of 1992 for the monitoring of background air Pollutant levels in Korea. Anthropogenic pollutant sources and meteorological conditions of Kosan were surveyed. Concentrations of SO$_2$, NO, NO$_{y}$ and $O_3$, were measured and analyzed for the period of February through December, 1992. The annual means of NO and SO$_2$, levels were very low in comparison to other urban's levels and similiar to other country's background levels. The annual mean of $O_3$, level was higher than urban's but comparable to other coastal region's. The NO concentration showed a distinct seasonal and diurnal variations. Summer peak was detected in the monthly means of NO and smooth peak around noon was found in the annual means of hourly data. Diurnal variation of the SO$_2$ concentration was barely detected but a slice increase in winter was detected. The $O_3$, concentration data, however, showed seasonal and diurnal variations similar to the urban's.an's.

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Gas Sensing Characteristics of Catalyst-added $In_2O_3$ Thick Film for Detecting $NO_x$ of High Concentration (고농도 $NO_x$ 감지용 $In_2O_3$ 후막가스센서의 Al, Ru 및 $SnO_2$ 첨가에 의한 특성 향상)

  • 박종현;김동현;이종영;김광호
    • Journal of the Korean Ceramic Society
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    • v.36 no.12
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    • pp.1322-1326
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    • 1999
  • In2O3 thick film gas sensor for detecting NOx gas of high concentration was fabricated by a screen printing technique. This work focussed on investigation of the change of sensitivity to NOx gas with firing temperatures of sensing layer and on improvement of the sensitivity by adding catalysts such as Al,. Ru, and SnO2 The cross sensitivites of sensor to CO, H2, CH4 and i-C4H10 gases were also examined under NO2 gas concentration of 200ppm Pure In2O3 gas sensor prepared at a firing temperature of 50$0^{\circ}C$ showed a maximum sensitivity to NOx gas at the operating temperature of 40$0^{\circ}C$ Al(0.004 wt%)-In2O3 sensor largely improved the sensitivities to both NO2 and NO gas and showed a superior selectivity compared with other gas sensors.

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The Effect of Oxygen Concentration in Hot Exhaust Gas on the $NO_{x}$ Emission of Diffusion Flame in Exhaust Gas (고온 배기가스의 산소농도가 배기가스이용 확산화염의 $NO_{x}$ 발생에 미치는 영향)

  • Sohn, H.S.;Jang, S.W.;Choi, D.S.;Kim, H.Y.
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.115-120
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    • 2001
  • The present study examined the possibility of $NO_{x}$ reduction in the high temperature industrial furnaces. duct burner of gas turbine cogeneration and two-stage gas turbine combustor. The experimental study was carried out for the diffusion flame of second stage combustor with the variations of oxygen concentration and supplying rate of hot exhaust gas from first stage combustor. It also examined the flammability range and $NO_{x}$ formation of the second stage combustor in which the fuel is supplying into the mixture of oxygen hot exhaust gas from first stage combustor. The results show that the enrichment of oxygen and increase of exhaust gas lead to increase the $NO_{x}$ up to 50 ppm with 23% $O_{2}$ condition.

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Methodology to Simultaneously Optimize the Inlet Ozone Concentration to Oxidize NO and Relative Humidity Composition for the $NO_x$ Degradation using Soil Bio-filter

  • Cho, Ki-Chul;Hwang, Kyung-Chul
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.E2
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    • pp.83-91
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    • 2008
  • This work investigated the methodology to simultaneously optimize the ozone and relative humidity composition for the $NO_x$ degradation using soil biofilter. Experiments were made as a function of inlet ozone concentration ($0{\sim}1,770\;ppb$) and relative humidity ($38{\sim}81%$). Factorial design ($2^2+3$) and response surface methodology by central composite designs were used to examine the role of two factors and optimal response condition on $NO_x$ degradation. It was found that a second-order response surface model can properly interpret the experimental data with an $R^2$-value of 0.9730 and F-value of 71.83, based on which the maximum $NO_x$ degradation was predicted up to 92.8% within our experimental conditions.

Anti-inflammatory Effect of Artemisia Capillaris Thunberg in Lipopolysaccharide-exposed Rats (인진호(茵蔯蒿)가 LPS 염증유발 흰쥐의 전염증성 cytokine 생산 및 혈액성상에 미치는 영향)

  • Seo, Yong-Seok;Lee, Eun;Cha, Yun-Yeop
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.3
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    • pp.27-35
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    • 2010
  • Objectives : The present study investigated anti-inflammatory effect of Artemisia Capilaris Thunberg in lipopolysaccharide-exposed rats. Methods : We divided lipopolysaccharide-exposed Sprague-Dawley rats into 4 groups. They were normal group, feed with 100 mg/kg Artemisia Capillaris Thunberg group, feed with 200 mg/kg Artemisia Capillaris Thunberg group and feed with 300 mg/kg Artemisia capilaris Thunberg group. They were administered for 6 weeks. We measured counts of red blood cell(RBC), the values of hemoglobin(Hb) and packed cell volume(PCV), plasma total protein concentration, albumin concentration, the ratio of albumin/globulin, the activities of plasma glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase(GPT), lactate dehydrogenase(LDH), the counts of white blood cell(WBC), the ratio of neutrophils, lymphocytes, monocytes, basophils, eosinophils, the concentration of plasma interleukin-$1{\beta}$($IL-1{\beta}$), plasma interleukin-6(IL-6), plasma tumor necrosis factor-$\alpha$($TNF-{\alpha}$), plasma interleukin-10(IL-10), the concentration of liver $IL-1{\beta}$ and IL-6, $TNF-{\alpha}$, IL-10. Results : Counts of RBC and the values of Hb and PCV, plasma total protein concentration and albumin concentration, the activities of plasma GOT, GPT and LDH showed no significant difference in the treatment groups. and the ratio of albumin/globulin was increased in Artemisia Capillaris Thunberg groups. The counts of WBC showed lower values in Artemisia Capillaris Thunberg groups than those of control group, In the ratio of neutrophils Thunberg groups. The ration of monocytes, basophils and eosinophils were below 5%, and showed no characteristic trend. The concentration of plasma interleukin-$1{\beta}$($IL-1{\beta}$), plasma inerleukin-6(IL-6) and plasma tumor necrosis factor-$\alpha$($TNF-{\alpha}$) showed a lower values in the Artemisia Capillaris Thunberg groups than those of control group, and the concentration of plasma interleukin-10(IL-10) showed no significant difference in the treatment groups. The concentration of liver $IL-1{\beta}$ and IL-6 showed a lower values in the Artemisia Capillaris Thunberg groups than those of control group, however the concentration of liver $TNF-{\alpha}$ and IL-10 showed no significant difference in the treatment groups. Conclusions : The Artemisia Capillaris Thunberg groups gives positive results of anti-inflammatory response by lipopolysaccharide(LPS) derivation.

A Study of NO Formation Characteristics in Laminar Flames Using 2-D LIF Technique (2-D LIF를 이용한 층류화염의 NO 생성특성에 관한 연구)

  • Lee, Won-Nam;Cha, Min-Suk;Song, Young-Hoon
    • Journal of the Korean Society of Combustion
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    • v.8 no.3
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    • pp.38-48
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    • 2003
  • OH, CH and NO radical distributions have been measured and compared with the numerical analysis results in methane/air partially premixed laminar flames using 2-D LIF technique. The pick intensity of OH LIF signal is insensitive to fuel equivalence ratio: however, CH LIF intensity decreases as equivalence ratio increases and the NO concentration increases with equivalence ratio. The contribution of the prompt NO, formed near premixed reaction zone, to the total NO formation is evident from the OH, CH, and NO PLIF images in which the dilution effect of nitrogen is minimal for the highest equivalence ratio. Measured OH and NO LIF signals in counterflow flames agree with the computed concentration distributions. Both numerical and experimental results indicate that the structural change in a flame alters the NO formation characteristics of a partially premixed counterflow flame. The nitrogen dilution also changes flame structure, temperature and OH radical distributions and results in the decreased NO concentrations in a flame. The levels of decrease in NO concentrations, however, depends on the premixedness(${\alpha}$) of a flame. The larger change in the flame structure and NO concentrations have been observed in a premixed flame(${\alpha}=1.0$), which implies that the premixedness is likely to be a factor in the dilution effect on NO formation of a flame.

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Image Observation of NO Particles Using ICCD Camera (ICCD Camera를 이용한 NO입자의 Image관측)

  • 전용우;하장호;박원주;이광식
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.1
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    • pp.98-103
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    • 2001
  • In this parer, the removal rate of NO in a reactor is rreasured first using nonthermal plasma generated from a wire-cylinder type reactor, then the discharge image and horizontal signal strength and vertical signal strength of NO particles is observed using ICCD(Intensified Charged Coupled Device) carrera It was fOlmd that NO rerroval rate was iflLTeased with NO concentration c1ecreasing, and that honzontal signal strength and vertical signal strength were also increased with NO concentration decreasing. Especially, this research is a1!Tffl at clarifying the discharge mechanism of NO particles by observing the images of AC discharge wnen the nonthermal plasma generated by an discharge was used.

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Effect of ARTEMISIAE ARGI FOLIUM Acupuncture Solution on Raw 264.7 Cells Treated by Toxicants (애엽(艾葉) 약침액(藥鍼液)이 에탄올 등에 의한 마우스 대식세포의 활성변화에 미치는 영향)

  • Park, Wan-Su
    • Korean Journal of Acupuncture
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    • v.25 no.3
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    • pp.137-146
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    • 2008
  • Objectives : The leaves of Artemisia argyi L. have been used for the treatment of bleeding-related diseases in traditional korean medicine. But the immunological activities with macrophage have not been sufficiently reported. This study is to investigate the immunological bioactivities of the herbal acupuncture solution obtained from leaves of Artemisia argyi L. (AAAS). Methods & Results : Against Nicotine and Acetaldehyde, AAAS increased significantly the production of hydrogen peroxide (H2O2) within mouse macrophage Raw 264.7 cells above the concentration of 10 ${\mu}g/m{\ell}$. AAAS increased significantly the production of nitric oxide (NO) in Raw 264. 7 cells above the concentration of 100 ${\mu}g/m{\ell}$ against EtOH. And AAAS increased significantly the production of nitric oxide (NO) in Raw 264. 7 cells above the concentration of 200 ${\mu}g/m{\ell}$ against Nicotine, Acetaminophen, and Acetaldehyde. Conclusions : These results suggest that AAAS could be thought to have the immunological activities related with the production of hydrogen peroxide and NO in macrophage.

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