• Title/Summary/Keyword: Pohang ozone

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Studies of Vertical Distribution Characteristics of Ozone in Pohang Area (오존의 수직분포 특성에 대한 연구 : 포항지역을 중심으로)

  • 김지영;윤용훈;송기범;김기현
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.04a
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    • pp.377-378
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    • 2000
  • 1957년 국제지구물리관측년 (IGY:International Geophysical Year) 계획 이래 대기중의 오존전량(total ozone)과 대기중의 수직 층별 오존량의 측정을 위해 본격적으로 전세계적 오존관측망이 운영되기 시작하였다. 이 시점을 기준으로 오존에 관한 연구는 전지구적인 오존전량의 감소경향과 남극상공 성층권에서의 오존량 파괴에 집중되어왔다. 그러나 대기중 오존의 행태를 더 정확하게 이해하고, 각각의 대기권이 서로의 오존량에 미치는 영향을 이해하기 위해서는 대기중 오존의 수직분포에 관한 연구가 대단히 중요하다. (중략)

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Characteristics and Prediction of Total Ozone and UV-B Irradiance in East Asia Including the Korean Peninsula (한반도를 포함한 동아시아 영역에서 오존전량과 유해자외선의 특성과 예측)

  • Moon, Yun-Seob;Seok, Min-Woo;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.15 no.8
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    • pp.701-718
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    • 2006
  • The average ratio of the daily UV-B to total solar (75) irradiance at Busan (35.23$^{\circ}$N, 129.07$^{\circ}$E) in Korea is found as 0.11%. There is also a high exponential relationship between hourly UV-B and total solar irradiance: UV-B=exp (a$\times$(75-b))(R$^2$=0.93). The daily variation of total ozone is compared with the UV-B irradiance at Pohang (36.03$^{\circ}$N, 129.40$^{\circ}$E) in Korea using the Total Ozone Mapping Spectrometer (TOMS) data during the period of May to July in 2005. The total ozone (TO) has been maintained to a decreasing trend since 1979, which leading to a negative correlation with the ground-level UV-B irradiance doting the given period of cloudless day: UV-B=239.23-0.056 TO (R$^2$=0.52). The statistical predictions of daily total ozone are analyzed by using the data of the Brewer spectrophotometer and TOMS in East Asia including the Korean peninsula. The long-term monthly averages of total ozone using the multiplicative seasonal AutoRegressive Integrated Moving Average (ARIMA) model are used to predict the hourly mean UV-B irradiance by interpolating the daily mean total ozone far the predicting period. We also can predict the next day's total ozone by using regression models based on the present day's total ozone by TOMS and the next day's predicted maximum air temperature by the Meteorological Mesoscale Model 5 (MM5). These predicted and observed total ozone amounts are used to input data of the parameterization model (PM) of hourly UV-B irradiance. The PM of UV-B irradiance is based on the main parameters such as cloudiness, solar zenith angle, total ozone, opacity of aerosols, altitude, and surface albedo. The input data for the model requires daily total ozone, hourly amount and type of cloud, visibility and air pressure. To simplify cloud effects in the model, the constant cloud transmittance are used. For example, the correlation coefficient of the PM using these cloud transmissivities is shown high in more than 0.91 for cloudy days in Busan, and the relative mean bias error (RMBE) and the relative root mean square error (RRMSE) are less than 21% and 27%, respectively. In this study, the daily variations of calculated and predicted UV-B irradiance are presented in high correlation coefficients of more than 0.86 at each monitoring site of the Korean peninsula as well as East Asia. The RMBE is within 10% of the mean measured hourly irradiance, and the RRMSE is within 15% for hourly irradiance, respectively. Although errors are present in cloud amounts and total ozone, the results are still acceptable.

A Study on the Contaminants Precision Cleaning of Etched Silicon Wafer by Ozone/UV (오존/자외선에 의한 실리콘 웨이퍼의 정밀세정에 관한 연구)

  • Park, H.M.;Lee, C.H.;Chun, B.J.;Yoon, B.H.;Lim, C.H.;Song, H.J.;Kim, Y.H.;Lee, K.S.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1820-1822
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    • 2004
  • In this study, major research fields are classified as ozone generation system for dry cleaning wafer of etched silicon wafer, dry cleaning process of etched silicon wafer which includes SEM analysis and ESCA analysis. The following results are deduced from each experiment and analysis. The magnitudes of carbon and silicon were similar to the survey spectrum of silicon wafer which does not cleaning, but magnitude of oxygen was much bigger Because UV light activates oxygen molecules in the oxide film on the silicon wafer.

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Discharge and Ozone Characteristics of Multi Discharge Type Ozonizer (다중방전형 오존발생기의 방전 및 오존생성특성)

  • Chun, Byung-Joon;Mun, Kyung-Su;Song, Hyun-Gik;Kim, Keum-Yeung;Lee, Kwang-Sik
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.1090-1092
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    • 1999
  • In this paper, multi discharge type ozonizer has been designed and manufactured. The of ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode). This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flow rate of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flow rate and discharge power.

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Characteristics of a Superposed Discharge Type Ozonizer(III) (중첩방전형 오존방생기의 특성(III))

  • Song, Hyun-Jig;Lee, Kwang-Sik;Lee, Dong-In;Kim, Gi-Chae;Lee, Dong-Heon;Kim, Geum-Young;Lee, Chun-Ha;Jeun, Young-Ju
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1815-1817
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    • 1998
  • In this paper, a superposed discharge type ozonizer(IESDO) has been designed and manufactured. IESDO is equipped with three electrodes(central, internal and external electrodes), and it is composed of two gaps. Ozone is generated by overlapping silent discharge, which is respectively came from two gaps. This paper describes the following characteristics : (1) The characteristics of discharge with variation of output voltage of AC H.V source, quantity of supplied gas and discharge voltage (2) the characteristics of ozone generation with variation of quantity of supplied gas, discharge power, operating number of IESDO.

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Ozone Generation Characteristics of Silent Discharge Type Ozonizer with Varying Discharge Area (무성방전형 오존발생기의 전극면적 변화에 따른 오존생성특성)

  • Lee, S.K.;Chun, B.J.;Park, Y.K.;Lee, K.S.;Song, H.J.;Lee, D.H.;Kim, Y.H.;Kim, G.Y.
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1775-1778
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    • 2002
  • 무성방전을 이용한 오존발생기에서 오존생성에 영향을 미치는 인자로는 원료가스의 온도, 습도, 유량, 방전전극의 재질과 형태, 전원의 형태 등 다양하다. 본 연구에서는 전극의 면적변화에 의한 오존생성특성을 살펴보았다. 그 결과, 방전전극의 면적이 넓어짐에 따라 더 많은 전력의 인가가 가능하여 대용량의 오존발생기의 제작이 가능하며, 또한, 동일한 전력을 인가하는 경우에도 전극면적의 증대가 오존발생특성의 향상을 가져옴을 알 수 있었다.

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Characteristics of the Stratospheric Ozone and the Surface Damaging UV-B Radiation in Pohang (포항 지역의 성층권 오존 및 지표 유해 자외선 특성)

  • 정성래;오재호;최영진
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.307-308
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    • 1999
  • 오존전량은 대류권계면 고도[Hoinka at al., 19961, 기온과 지위 고도[Spankuch and Schulz, 1995], 잠재 와도[Vaughan and Price, 1991] 또는 상대 와도와 같은 기상 변수와 높은 상관관계를 나타낸다. 그리고 성층권 오존량의 감소는 지표 유해자외선을 증가시킨다는 연구 결과가 발표되고 있다(예: 조회구 등 1998; Zerefos et al. 1997).(중략)

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Source of the tropospheric ozone using the ozonesonde data at Pohang (포항오존존데 자료를 이용한 대류권 오존의 기원)

  • 김재환;이상희;김유근
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.75-76
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    • 2002
  • 대기환경에 대한 오존의 영향이 증대되면서 오존에 대환 관심이 증대되었다. 대류권과 성층권에 존재하는 오존은 서로 상반된 영향력을 미치는 것으로 알려져 있다(Lu et al., 1997). 성층권의 오존은 약 25km 부근 상공에서 최고농도대를 형성하며, 태양으로부터 오는 유해자외선을 차단하는 역할을 한다. 그러나, 대류권에서 오존이 고농도로 존재할 경우는 산화제로서 작용하여 인간, 식물을 비롯한 생태계에 영향을 미친다. (중략)

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VERTICAL OZONE DENSITY PROFILING BY UV RADIOMETER ONBOARD KSR-III

  • Hwang Seung-Hyun;Kim Jhoon;Lee Soo-Jin;Kim Kwang-Soo;Ji Ki-Man;Shin Myung-Ho;Chung Eui-Seung
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.372-375
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    • 2004
  • The UV radiometer payload was launched successfully from the west coastal area of Korea Peninsula aboard KSR-III on 28, Nov 2002. KSR-III was the Korean third generation sounding rocket and was developed as intermediate step to larger space launch vehicle with liquid propulsion engine system. UV radiometer onboard KSR-III consists of UV and visible band optical phototubes to measure the direct solar attenuation during rocket ascending phase. For UV detection, 4 channel of sensors were installed in electronics payload section and each channel has 255, 290, 310nm center wavelengths, respectively. 450nm channel was used as reference for correction of the rocket attitude during the flight. Transmission characteristics of all channels were calibrated precisely prior to the flight test at the Optical Lab. in KARI (Korea Aerospace Research Institute). During a total of 231s flight time, the onboard data telemetered to the ground station in real time. The ozone column density was calculated by this telemetry raw data. From the calculated column density, the vertical ozone profile over Korea Peninsula was obtained with sensor calibration data. Our results had reasonable agreements compared with various observations such as ground Umkhr measurement at Yonsei site, ozonesonde at Pohang site, and satellite measurements of HALOE and POAM. The sensitivity analysis of retrieval algorithm for parameters was performed and it was provided that significant error sources of the retrieval algorithm.

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