• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 춘계학술대회 논문집
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• pp.347-348
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• 2003

대기 중의 질산에 의해 생성되는 질산염은 해염성분이나 토양성분과 만나 조대입자 영역에 머물거나 암모늄과 만나 미세입자로 존재할 수 있다. 미세입자로 존재하는 질산염은 여름철과 같은 광화학 반응이 활발할 때 2차적으로 생성되는 물질로, 반휘발성 특성 때문에 측정하는 과정에서 오차가 발생할 가능성도 크다. Seinfeld (1986)에 의하면 미국의 도심 지역에서 미세입자 중 황산염이나 질산염 등 2차 이온 성분의 비율이 전체 입자의 40∼60 %를 차지한다고 보고되고 있으며, 대표적인 도심 지역인 서울에서도 비슷하다 (강충민 등, 1999). (중략)

• 식품기술
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• 제18권1호
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• pp.91-98
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• 2005

Aims: As a preliminary experiment on new sanitizer delivery tools, the efficacy of aerosolizedsanitizer on foodborne pathogens was investigated in larger model chamber system.Methods: Peroxyacetic acid and hydrogen peroxide were aerosolized in a model system againstartificially inoculated target microorganisms on laboratory media. Cultures of 4 different foodborne pathogens were inoculated and affixed onto 3 different heights (bottom, wall, and ceiling), and 3different orientations (face-down, vertical, and face-down) inside a commercial semi-trailer cabinet(14.6 x 2.6 x 2.8 m). Sanitizer was aerosolized into 2 m droplet size fog and treated for 1 h atambient temperature.Results: Populations of Bacillus cereus, Listeria innocua, Staphylococcus aureus, and Salmonellatyphimurium were reduced by an average of 3.09, 7.69, 6.93 and 8.18 log units per plate, respectively.Interestingly, L. innocua, Staph. aureus, and Salm. typhimurium showed statistically not different (P$\leq$ 0.05) reduction patterns relative to height and orientation that were never expected in a sprayingsystemConclusion and significance: Aerosolized sanitizers diffuse like gaseous sanitizers, so it has greatpotential for use in commercial applications.

• 한국대기환경학회지
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• 제31권6호
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• pp.520-529
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• 2015

The ambient $PM_{2.5}$ samples were collected by $PM_{2.5}$ sampler from September 2010 to December 2012 at Daegu University, Gyeongsan. A total of 260 samples were collected and 27 species were analyzed by inductively coupled plasma, ion chromatography, and thermal optical reflectance methods. Factor analysis identified four sources such as biomass burning source/secondary aerosol source, soil source, industry source, and incinerator source/mobile source. Also, backward trajectories were calculated using HYSPLIT 4 (Hybrid single-particle lagrangian integrated trajectory) model and PSCF (Potential source contribution function) model was applied to identify the possible source locations of carbonaceous species and water soluble ions species. PSCF results showed that the possible source locations of most chemical constituents measured in Gyeongsan were the industrial areas in the eastern coast of China, northeast regions of China, the Gobi Desert, and east sea of Korea.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.231-235
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• 1998

We have made the cross calibration in terms of space reflectance between POLDER and OCTS sensors on board ADEOS satellite, using the POLDER and OCTS data acquired simultaneously on April 24, 1997. The space reflectance values for the same target computed from the POLDER and OCTS data are in very good agreement, when we adopted the new calibration coefficients of OCTS suggested by the vicarious experiment by NASDA. Then, we estimated aerosol parameters for several target areas (two areas in the Sea of Japan and three in the Pacific Ocean) from ADEOS/POLDER's directional reflectance and polarization data in 760nm and 865nm bands. A single atmospheric layer model with an isotropic Gaussian type ocean surface (Cox-Munk model) was assumed in this study.

• Korean Chemical Engineering Research
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• 제55권1호
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• pp.130-134
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• 2017

Organic aerosols dispersed in the atmosphere likely undergo phase separation. Such internally mixed particles are often described as comprising an organic phase and an aqueous phase separately. We studied the morphology of two liquid separated aerosols in the sub-microscale by using a simple thermodynamic model with Russian doll geometry. The morphology of particles can be easily predicted from the simple criteria on the surface tension and two algebraic equations (the volume constraint and Young equation). This result may give the potential explanation about the complex morphology of the organic airborne particles.

• Journal of Korean Society for Atmospheric Environment
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• 제20권E2호
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• pp.43-52
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• 2004

A total of 10 boundary layer sampling events over the Pacific Ocean were analyzed for the purpose of defining the sea-to-air $CH_3$I flux using a mass balance photochemical model. These events were recorded on the National Center for Atmospheric Research (NCAR) C-130 aircraft as part of the Aerosol Charac-terization Experiment (ACE 1). The latitude range, covered by these events, was 2$^{\circ}$ N to 55$^{\circ}$ S. The flux ranges were 4 to 33 nmol m$^{-2}$ day$^{-1}$ , with an average value of 11$\pm$8 nmol m$^{-2}$ day$^{-1}$ . This study also indicated that the current approach to estimate the flux was not systematically different from the sea-air exchange model.

• 한국환경보건학회지
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• 제23권4호
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

• 대한원격탐사학회지
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• 제38권6_1호
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• pp.1191-1205
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• 2022

복잡하고 광범위한 원인을 가진 대기오염물질 중 particulate matter (PM)은 입자의 크기에 따라 분류된다. 그 중 PM_2.5는 그 크기가 매우 작아 사람이 흡입하면 인간의 호흡기나 심혈관에 질병을 유발할 수 있다. 이러한 위험에 대비하기 위해서는 국가 중심의 관리와 사전에 예방할 수 있는 모니터링 및 예측이 중요하다. 본 연구는 고농도 미세먼지의 발생이 잦은 서울시의 PM_2.5를 local data assimilation and prediction system (LDAPS) 기상 관련 인자 15가지와 aerosol optical depth (AOD), 화학인자 4가지를 독립변수로 하여 앙상블 모델 두 가지 random forest (RF)와 extreme gradient boosting (XGB)로 예측하고자 하였다. 예측에 사용된 두 모델의 성능 평가와 인자 중요도 평가를 수행하였으며, 계절별 모델 분석도 수행하였다. 예측 정확도 결과, RF가 R² = 0.85, XGB가 R² = 0.91의 높은 예측 정확도를 보이며 XGB가 RF보다 PM_2.5 예측에 적합한 모델임을 확인하였다. 계절별 모델 분석 결과, 봄에 농도가 높은 관측 값과 비교하여 예측 수행이 잘 되었다고 할 수 있다. 본 연구는 다양한 인자를 이용하여 서울시의 PM_2.5를 예측하였고, 좋은 성능을 보이는 앙상블 기반의 PM_2.5 예측 모델을 구축하였다.

• 대한원격탐사학회지
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• 제34권3호
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• pp.451-463
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• 2018

본 연구는 서울지역에서 2015년 1월부터 12월까지 정지궤도 천리안 위성(Communication Ocean and Meteorological Satellite, COMS) 해양 탑재체(Geostationary Ocean Color Imager, GOCI)의 에어로졸광학두께(Aerosol Optical Depth, AOD)로부터 지상 초미세먼지(Particulate Matter; $PM_{2.5}$) 농도를 추정하기 위한 계절별 경험/통계모델을 개발했다. 행성경계층고도(Planetary Boundary Layer Height, PBLH) 그리고 에어로졸 수직 비율(Vertical Ratio of Aerosol, VRA)을 사용한 두 가지 수직보정방법과 흡습성장계수(Hygroscopic growth factor, f(RH))로부터의 습도보정방법이 각각의 경험적 모델에 적용된 결과 AOD에 대한 수직 보정과 $PM_{2.5}$에 대한 지표 습도보정이 모델 성능 향상에 중요한 역할을 했다. AOD-$PM_{2.5}$ 사이에 관련이 있다고 알려진 기상인자들(온도, 풍속, 시정)을 추가적으로 사용하여 다중 선형 회귀모델을 구성한 결과 경험모델에 비해 $R^2$값이 최대 0.25 증가했다. 본 연구에선 AOD-$PM_{2.5}$ 모델의 계절별, 월별, 시간별 특성을 분석하고 계절별로 구분하여 모델을 구성한 결과 고농도 사례에서 과소평가 되던 경향이 개선됨을 알 수 있고 관측된 $PM_{2.5}$와 추정된 $PM_{2.5}$의 월 및 시간변동성은 서로 경향성이 일치했다. 따라서 정지궤도 위성 AOD를 이용하여 지상 $PM_{2.5}$ 농도를 추정한 본 연구의 결과는 향후 발사 예정인 GK-2A와 GK-2B에 적용 가능할 것으로 기대된다.

• Journal of Gastric Cancer
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• 제24권3호
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• pp.246-256
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• 2024

Purpose: Peritoneal carcinomatosis (PC) presents a major challenge in the treatment of late-stage, solid tumors, with traditional therapies limited by poor drug penetration. We evaluated a novel hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) system using a human abdominal cavity model for its efficacy against AGS gastric cancer cells. Materials and Methods: A model simulating the human abdominal cavity and AGS gastric cancer cell line cultured dishes were used to assess the efficacy of the HPIPAC system. Cell viability was measured to evaluate the impact of HPIPAC under 6 different conditions: heat alone, PIPAC with paclitaxel (PTX), PTX alone, normal saline (NS) alone, heat with NS, and HPIPAC with PTX. Results: Results showed a significant reduction in cell viability with HPIPAC combined with PTX, indicating enhanced cytotoxic effects. Immediately after treatment, the average cell viability was 66.6%, which decreased to 49.2% after 48 hours and to a further 19.6% after 120 hours of incubation, demonstrating the sustained efficacy of the treatment. In contrast, control groups exhibited a recovery in cell viability; heat alone showed cell viability increasing from 90.8% to 94.4%, PIPAC with PTX from 82.7% to 89.7%, PTX only from 73.3% to 74.8%, NS only from 90.9% to 98.3%, and heat with NS from 74.4% to 84.7%. Conclusions: The HPIPAC system with PTX exhibits a promising approach in the treatment of PC in gastric cancer, significantly reducing cell viability. Despite certain limitations, this study highlights the system's potential to enhance treatment outcomes. Future efforts should focus on refining HPIPAC and validating its effectiveness in clinical settings.