• Title/Summary/Keyword: Aerosol Model

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Examining a Vicarious Calibration Method for the TOA Radiance Initialization of KOMPSAT OSMI

  • Sohn, Byung-Ju;Yoo, Sin-Jae;Kim, Yong-Seung;Kim, Do-hyeong
    • Korean Journal of Remote Sensing
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    • v.16 no.4
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    • pp.305-313
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    • 2000
  • A vicarious calibration method was developed for the OSMI sensor calibration. Employing measured aerosol optical thickness by a sunphotometer and a sky radiometer and water leaving radiance by ship measurements as inputs, TOA (top of the atmosphere) radiance at each OSMI band was simulated in conjunction with a radiative transfer model (Rstar5b) by Nakajima and Tanaka (1988). As a case of examining the accuracy of this method, we simulated TOA radiance based on water leaving radiance measured at NASA/MOBY site and aerosol optical thickness estimated nearby at Lanai, and compared simulated results with SeaWiFS-estimated TOA radiances. The difference falls within about $\pm$5%, suggesting that OMSI sensor can be calibrated with the suggested accuracy. In order to apply this method for the OSMI sensor calibration, ground-based sun photometry and ship measurements were carried out off the east coast of Korean peninsula on May 31, 2000. Simulations of TOA radiance by using these measured data as input to the radiative transfer model show that there are substantial differences between simulated and OSMI-estimated radiances. Such a discrepancy appears to be mainly due to the cloud contamination because satellite image indicates optically thin clouds over the experimental area. Nevertheless results suggest that sensor calibration can be achieved within 5% uncertainty range if there are ground-based measurements of aerosol optical thickness, and water leaving radiances under clear-sky and optically thin atmospheric conditions.

Occupational Exposure during Intraperitoneal Pressurized Aerosol Chemotherapy Using Doxorubicin in a Pig Model

  • Wongeon Jung;Mijin Park;Soo Jin Park;Eun Ji Lee;Hee Seung Kim;Sun Ho Chung;Chungsik Yoon
    • Safety and Health at Work
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    • v.14 no.2
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    • pp.237-242
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    • 2023
  • Background: This study evaluated occupational exposure levels of doxorubicin in healthcare workers performing rotational intraperitoneal pressurized aerosol chemotherapy (PIPAC) procedures. Methods: All samples were collected during PIPAC procedures applying doxorubicin to an experimental animal model (pigs). All procedures were applied to seven pigs, each for approximately 44 min. Surface samples (n = 51) were obtained from substances contaminating the PIPAC devices, surrounding objects, and protective equipment. Airborne samples were also collected around the operating table (n = 39). All samples were analyzed using ultra-high performance liquid chromatography-mass spectrometry. Results: Among the surface samples, doxorubicin was detected in only five samples (9.8%) that were directly exposed to antineoplastic drug aerosols in the abdominal cavity originating from PIPAC devices. The telescopes showed concentrations of 0.48-5.44 ng/cm2 and the trocar showed 0.98 ng/cm2 in the region where the spraying nozzles were inserted. The syringe line connector showed a maximum concentration of 181.07 ng/cm2, following a leakage. Contamination was not detected on the surgeons' gloves or shoes. Objects surrounding the operating table, including tables, operating lights, entrance doors, and trocar holders, were found to be uncontaminated. All air samples collected at locations where healthcare workers performed procedures were found to be uncontaminated. Conclusions: Most air and surface samples were uncontaminated or showed very low doxorubicin concentrations during PIPAC procedures. However, there remains a potential for leakage, in which case dermal exposure may occur. Safety protocols related to leakage accidents, selection of appropriate protective equipment, and the use of disposable devices are necessary to prevent occupational exposure.

Development of Solar-Meteorological Resources Map using One-layer Solar Radiation Model Based on Satellites Data on Korean Peninsula (위성자료 기반의 단층태양복사모델을 이용한 한반도 태양-기상자원지도 개발)

  • Jee, Joonbum;Choi, Youngjean;Lee, Kyutae;Zo, Ilsung
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.56.1-56.1
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    • 2011
  • The solar and meteorological resources map is calculated using by one-layer solar radiation model (GWNU model), satellites data and numerical model output on the Korean peninsula. The Meteorological input data to perform the GWNU model are retrieved aerosol optical thickness from MODIS (TERA/AQUA), total ozone amount from OMI (AURA), cloud fraction from geostationary satellites (MTSAT-1R) and temperature, pressure and total precipitable water from output of RDAPS (Regional Data Assimilation and Prediction System) and KLAPS (Korea Local Analysis and Prediction System) model operated by KMA (Korea Meteorological Administration). The model is carried out every hour using by the meteorological data (total ozone amount, aerosol optical thickness, temperature, pressure and cloud amount) and the basic data (surface albedo and DEM). And the result is analyzed the distribution in time and space and validated with 22 meteorological solar observations. The solar resources map is used to the solar energy-related industries and assessment of the potential resources for solar plant. The National Institute of Meteorological Research in KMA released $4km{\times}4km$ solar map in 2008 and updated solar map with $1km{\times}1km$ resolution and topological effect in 2010. The meteorological resources map homepage (http://www.greenmap.go.kr) is provided the various information and result for the meteorological-solar resources map.

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Quantitative Source Estimation of Particulate Matters in Suwon Area Using the Target Transformation Factor Analysis Based on Size Segregation Scheme (입경 분류에 입각하여 목표변환 인자분석법을 이용한 수원지역 분진 오염원의 정량적 기여도 추정)

  • 김동술;이태정
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.1
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    • pp.44-50
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    • 1993
  • The suspended particulate matters had been collected by a cascade impactor having 9 size fragnated stages for 2 years (Dec. 1989 to Nov. 1991) in Kyung Hee University-Suwon Campus. The particulate matters were then collected on each stage by membrane filters. The weight concentration on each stage was estimated by a microbalance and further chemical element concentrations were determined by an XRF system. The study focused on developing of a receptor model using the TTFA (target transformation factor analysis) to apportion aerosol mass with the 30 ambient data sets. Each data set consists of the 8 size-ranged subdata sets characterized by 13 element variables. Even though a couple of sources could not be identified, three to five sources were extracted from each aerosol size-range, and then 9 statistical source profiles were generated. Finally, source contribution of particulate matters on each size-range could be estimated in Suwon area.

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Atomization Characteristics of Cutting Fluids (절삭유의 미립화 특성)

  • Hwang, Joon;Chung, Eui-Sik;Joung, Jin-Yel;Hwang, Duck-Chul
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.943-946
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    • 2002
  • This paper presents atomization characteristics of cutting fluids. To analyze the behavior characteristics of cutting fluid, analytical approach and experimental measurement were performed to predict the aerosol size, velocity and concentration due to cutting fluid atomization mechanism in machining operation. The established analytical model which is based on atomization theory analyzes the cutting fluid motion and aerosol generation in machining process. The predictive models can be used as a basis for environmental impact analysis on the shop floor. It can be also facilitate the optimization of cutting fluid usage in achieving a balanced consideration of productivity and environmental consciousness.

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THE MODIFIED BRIGHTNESS TEMPERATURE DIFFERENCE FOR AEROSOL DETECTION

  • Kim, Jae-Hwan;Ha, Jong-Sung;Lee, Hyun-Jin
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.794-796
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    • 2006
  • This study investigated the Brightness Temperature Difference threshold as criterion between aerosols and clouds in conjunction with radiative transfer model. Surface temperature is caused by a significant error over 50% in the BTD threshold. In addition, The BTD threshold contains the uncertainties about 20% due to the surface emissivity and 8% due to the satellite zenith angle. Therefore, we have composed the Look-up table for BTD between 11㎛and 12㎛ according to satellite zenith angle, surface temperature, and surface emissivity. The modified BTD show the enhanced signal, especially over bright surface such as desert in China. However, a weak aerosol signal over Ocean remains in the modified BTD.

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Numerical Analysis on Removal Efficiency of Water Droplets in a Curved Vane Mist Eliminator with Consideration of Evaporation and Condensation at Surface of Droplets (액적 표면에서 증발 및 응축을 고려한 곡면 형상 액적 제거장치의 제거 효율에 대한 수치 해석)

  • Song, Dong Keun
    • Particle and aerosol research
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    • v.12 no.4
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    • pp.135-143
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    • 2016
  • Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For accurate understanding of removal process in a curved vane mist eliminator, a numerical model including turbulent dispersion, evaporation and condensation of water vapor at surface of droplets is required. A two-stage curved vane mist eliminator has been modeled, and fluid flow of mixture of air and water vapor and droplet trajectories were solved simultaneously with taking into account two-way coupling. Removal efficiency of droplets with various inlet condition of relative humidities (RH, 40%, 90%, and 100%) were compared. As RH increased, the effect of evaporation decreased and inertial separation efficiencies of droplets obtained increased especially for droplets of diameter below 10 micrometers.

Mist Formation Characteristics in Turning (선삭 가공시의 미스트 발생 특성)

  • 오명석;고태조;박성호;김희술;정종운
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.147-152
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    • 2002
  • The mechanism of the aerosol(mist) generation generally consists of spin-off, splash, and evaporation/condensation. Host researchers showed some theoretical model for predicting the particulate size and generation rate without real cutting in turning operation. These models were based on the spin-off mechanism, and verified good for modeling the process. However, in real machining, the cutting tool destroys the flow direction of the cutting fluid and generate the heat by the relative motion of between tool and workpicee, and so the mass loading of the mist is greatly increased as compared with non-cutting. In this paper, we show some experimental data that the mist formation characteristics of cutting is different from that of non-cutting.

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