• Asian Journal of Atmospheric Environment
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• 제12권2호
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• pp.127-138
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• 2018

This study measured indoor and outdoor levels of hydrocarbon volatile organic compounds (VOCs), such as benzene, toluene, ethylbenzene, and xylene isomers (collectively referred to as BTEX), as well as 13 carbonyl compounds, at 20 homes in Seoul, South Korea. Along with the sampling of BTEX and carbonyls, indoor concentrations of the air pollutants nitrogen oxide (NO) and carbon dioxide ($CO_2$) were also measured at each home. These measurements were used to understand the characteristics of BTEX and carbonyls by calculating the various ratios and correlation coefficients between measured contaminant levels. We found that carbonyls were mostly originated from indoor sources, while BTEX were originated from both indoor and outdoor sources. A high correlation between indoor levels of NO and BTEX indicated that traffic emissions were also an important sources of BTEX.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.315-318
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• 2005

$PM_{10}$ and 16 PAHs were measured in indoor and outdoor air of 5 different old houses, new and sick houses, respectively. $PM_{10}$ concentrations measured in indoor of three different kinds of houses ranged from 23 to 43 ${\mu}g/m^3$ and in outdoor ranged in 40-64 ${\mu}g/m^3$. Sum of average concentrations of PAHs in old, new and sick houses indoor air were 3.7 $ng/m^3$, 6.6 $ng/m^3$ and 16.1 $ng/m^3$, respectively, which were lower than those of outdoors. Most of the indoor/outdoor ratio for PAHs in each house were less than 1.0 and significant correlation(p<0.05) between indoor and outdoor samples was observed.

• Architectural research
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• 제8권1호
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• pp.37-45
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• 2006

A fungal spore transportation model that accounts for the concentration of airborne indoor spores and the amount of spores deposited on interior surfaces has been developed by extending the current aerosol model. This model is intended to be used for a building with a mechanical ventilation system, and considers HVAC filter efficiency and ventilation rate. The model also includes a surface-cleaning efficiency and frequency that removes a portion of spores deposited on surfaces. The developed model predicts indoor fungal spore concentration and provides an indoor/outdoor ratio that may increase or decrease mold growth risks in real, in-use building cases. To get a more useful outcome from the model simulation, an uncertainty analysis has been conducted in a real building case. By including uncertainties associated with the parameters in the spore transportation model, the simulation results provide probable ranges of indoor concentration and indoor/outdoor ratio. This paper describes the uncertainty quantification of each parameter that is specific to fungal spores, and uncertainty propagation using an appropriate statistical technique. The outcome of the uncertainty analysis showed an agreement with the results from the field measurement with air sampling in a real building.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E3호
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• pp.109-115
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• 2001

Acidic air pollutants were collected to characterize indoor air quality at a private house in Seoul during the spring period. All indoor and outdoor samples were measured simultaneously using an annular denuder system. The data set was collected on twelve different days with a 24-hr sampling period in April and May 1997. The chemical species measured were HN $O_3$, HN $O_2$, S $O_2$ and N $H_3$in the gas phase and P $M_{2.5}$ (dp 2.5 ${\mu}{\textrm}{m}$), S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ and N $H_4$$^{+}$ in the particulate phase. Indoor concentrations of HN $O_2$, N $H_3$, and P $M_{2.5}$ were greater than outdoor levels. However, indoor concentrations of HN $O_3$, S $O_2$, N $O_3$$^{[-10]}$ and N $H_4$$^{+}$ were less than those found from outdoors. In the case of S $O_4$$^{2-}$, the indoor and outdoor concentrations were similar. Indoor concentrations of P $M_{2.5}$ , S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ were dependent upon the outdoor concentrations. A tracer-gas decay technique with sulfur hexafluoride (S $F_{6}$ ) as the tracer gas was used to estimate the air exchange rate of a private home in the spring. The average air exchange rate was computed to be 2.87 h $r^{-1}$ .X> .

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.41-47
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• 2013

Purpose: The objectives of this study were to construct the solar drying system with evacuated tubular solar collector and to investigate its performance in comparison with indoor and outdoor dryings. Methods: Solar drying system was constructed with using CPC (compound parabolic concentrator) evacuated tubular solar collector. Solar drying system is mainly composed of evacuated tubular solar collector with CPC reflector, storage tank, water-to-air heat exchanger, auxiliary heater, and drying chamber. Performance test of solar drying system was conducted with drying of agricultural products such as sliced radish, potato, carrot, and oyster mushroom. Drying characteristics of agricultural products in solar drying system were compared with those of indoor and outdoor ones. Results: Solar drying system showed considerable effect on reducing the half drying time for all drying samples. However, outdoor drying was more effective than indoor drying on shortening the half drying time for all of drying samples. Solar drying system and outdoor drying for oyster mushroom showed the same half drying time. Conclusions: Oyster mushroom could be dried easily under outdoor drying until MR (Moisture Ratio) was reached to about 0.2. However, solar drying system showed great effect on drying for most samples compared with indoor and outdoor dryings, when MR was less than 0.5.

• 대한원격탐사학회지
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• 제36권6_3호
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• pp.1691-1710
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• 2020

본 연구에서는 평택과 부산의 초등학교를 대상으로 학교 주변과 교실 내를 포함하여 총 16개 지점에서 PM2.5(particulate matter less than 2.5 ㎛ in diameter) 및 PM10(particulate matter less than 10 ㎛ in diameter)을 동시에 측정하였고, 이 결과를 여러 국외 선행연구 리뷰를 통해서 획득한 실내·외 PM2.5 및 PM10 측정 농도 및 I/O ratio(Indoor/Outdoor ratio)와 비교하였다. 선행연구는 총 30건의 연구에서 144건의 사례를 수집하여 이를 실내활동, 측정 계절, 건물용도, 주변환경에 대해 다양한 항목별로 분류하여 본 연구의 측정결과와 비교하였다. 선행연구 결과에서 PM2.5는 흡연활동이나 요리활동 등의 실내 연소작용이 없는 환경에서는 외기농도가 실내농도에 중요한 영향을 미치는 반면, PM10은 외기농도와 함께 물리적 활동에 따른 재 비산이 중요한 실내 배출원일 것으로 보인다. 평택과 부산의 초등학교에서의 측정결과도 선행연구 리뷰 결론을 뒷받침하는 양상을 보였고, 공기청정기 사용이 미세먼지 저감에 효율적인 것으로 나타났다. PM2.5와 PM10은 실내 배출원 및 외기와의 상호작용 영향이 다를 수 있으며 환기방식에서는 강제환기가 자연환기보다 PM2.5와 PM10의 실내농도 감소에 더 효율적일 수 있는 것으로 보인다.

• 환경위생공학
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• 제16권4호
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• pp.21-30
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• 2001

Vehicles, especially diesel-using, are a major source of airborne particulate matter(PM), nitrogen dioxide($NO_2$) and so on in metropolitan cities such as Seoul. Therefore workers, who are mainly merchants, near roadside may be highly exposed to air pollutants from exhausted emissions of vehicles. This means that occupational type and location can affect the workers＇health by exposure to outdoor pollutions of ambient as well as indoor pollutions of working condition, respectively. In this study, we simultaneously measured the PM3.5 and $NO_2$concentrations in indoor and outdoor of shoes repair shops in Seoul, which were generally located at roadside in Korea. Shoes repairmen were highly exposed to PM3.5 and $NO_2$ both indoor and outdoor of repair shops comparing with other sub-population groups. High exposure to air pollutants for shoes repairmen was considered to be outdoor source from exhausted emission of vehicles and indoor source from working condition. The $PM3.5/NO_2$ concentration ratio was $1.17{\pm}$0.59 in roadside, of which ratio was higher 7han ratios of other studies. This result suggested that major air pollutant in Seoul was fine particle. Also, this PM3.5 to $NO_2$ ratio will be used in environmental exposure and risk assessment by estimation of PM3.5 concentration as measuring the only $NO_2$ concentration with small and accurate $NO_2$ passive sampler.

• 한국환경과학회지
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• 제11권8호
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• pp.801-810
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• 2002

The current paper describes the indoor/outdoor air quality in school environments through analyses of the heavy metal concentrations using Inductive Coupled Plasma(ICP). School environments in a heavy traffic area, two industrial areas, quasi-industrial area, and residential area were evaluated. The results were as follows: (1) The locations with the highest indoor and outdoor concentrations of heavy metals were the industrial areas followed by the heavy traffic area, residential area, and quasi-industrial area in a descending order of magnitude. Plus, the indoor heavy metal concentrations were higher then the outdoor ones. (2) The main heavy metal components were Zn, Al and Ca. Higher concentration levels were found indoors than outdoors. The heavy metal concentrations were also higher in the classrooms than in the corridor or outdoors. (3) The total heavy metal concentrations in the studied areas were highly dependent on the weather elements. including the relative humidity, mixing ratio, and wet-bulb depression. Accordingly, special ventilation systems are recommended to reduce air pollution in school environments.

• 한국축산식품학회지
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• 제28권5호
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• pp.629-636
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• 2008

본 연구는 비육기 이전에 초지에서 방목한 한우육과 옥내에서 비육한 한우육의 품질을 비교하고자 실시하였다. 방목사육구는 $28{\pm}4$개월령 암소 5두를 7개월 동안(4월-11월)방목한 다음 다시 6개월 동안 옥내에서 비육하였으며, 옥내사육구는 6개월령 거세우 10두를 24개월 동안 옥내에서 비육하였다. 시료로 등심(M. longissimus)부위를 채취하여 $4{\pm}0.2^{\circ}C$에서 7일 동안 저장하였다. 도체성적은 방목우의 도체중, 지육율, 배최장근단면적 및 육질등급이 옥내사육우보다 낮았으나(p<0.05), 조직감 및 성숙도는 방목우가 높았다(p<0.05). 조지방 및 n-6 지방산, n-6/n-3은 방목우가 낮았으나(p<0.05), n-3 지방산, 포화지방산은 방목우가 높았다(p<0.05). pH 및 보수력은 방목우가 낮았으며(p<0.05), 전자코에 의한 향기패턴은 두 처리구들간에 뚜렷한 차이를 보였다. 저장중 품질은 방목우의 지방 및 육색소 산화안정성이 낮았으며, 옥내사육 우보다 어둡고 덜 붉은 육색을 나타내었다.

• 한국대기환경학회지
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• 제17권2호
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• pp.193-201
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• 2001

Acidic air pollutants were collected to characterize indoor air quality in a residential area in the summer. All indoor and outdoor samples were measured simultaneously using an annular denuder system(ADS) in Seoul. The data set was collected from July 26 to September 11, 1997. The mean indoor/outdoor ratios measured from this study were : 0.34 for $HNO_3$; 0.91 for $HNO_2$; 0.22 for $SO_2$; 1.34 for $NH_3$; 0.78 for $PM_{2.5}(d_p$ <2.5 $mutextrm{m}$); 0.90 for $SO_{4}^{2-}$; 0.68 for $NO_{3}^{-}$ and 0.79 for $NH_{4}^{+}$. Indoor concentrations of $HNO_3$, $SO_2$ and $PM_{2.5}$ were highly correlated with the outdoor concentrations. The relationship between indoor and outdoor air is dependent, to a large extent, on the rate of air exchange between these two environments. A tracer-gas decay technique with sulfur hexafluoride ($SF_{6}$) as a tracer gas was used to estimate the air exchange of a private home in the summer. The average air exchange rate was estimated to be 23.7 hr(sup)-1. The deposition velocities for $SO_{4}^{2-}$, $NO_{3}^{-}$ and $NH_{4}^{+}$ calculated were 0.17, 0.69 abd 0.39 cm/sec, respectively.