• 한국환경과학회지
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• 제21권11호
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• pp.1321-1331
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• 2012

To date, carbon and nitrogen co-doped photocatalysts (CN-$TiO_2$) for environmental application focused mainly on the aqueous phase to investigate the decomposition of water pollutants. Accordingly, the present study explored the photocatalytic performance of CN-$TiO_2$ photocatalysts for the purification of indoor-level gas-phase aromatic species under different operational conditions. The characteristics of prepared photocatalysts were investigated using X-ray diffraction, scanning emission microscope, diffuse reflectance UV-VIS-NIR analysis, and Fourier transform infrared (FTIR) analysis. In most cases, the decomposition efficiency for the target compounds exhibited a decreasing trend as input concentration (IC) increased. Specifically, the average decomposition efficiencies for benzene, toluene, ethyl benzene, and xylene (BTEX) over a 3-h process decreased from 29% to close to zero, 80 to 5%, 95 to 19%, and 99 to 32%, respectively, as the IC increased from 0.1 to 2.0 ppm. The decomposition efficiencies obtained from the CN-$TiO_2$ photocatalytic system were higher than those of the $TiO_2$ system. As relative humidity (RH) increased from 20 to 95%, the decomposition efficiencies for BTEX decreased from 39 to 5%, 97 to 59%, 100 to 87%, and 100 to 92%, respectively. In addition, as the stream flow rates (SFRs) decreased from 3.0 to 1.0 L $min^{-1}$, the average efficiencies for BTEX increased from 0 to 58%, 63 to 100%, 69 to 100%, and 68 to 100%, respectively. Taken together, these findings suggest that three (IC, RH, and SFR) should be considered for better BTEX decomposition efficiencies when applying CN-$TiO_2$ photocatalytic technology to purification of indoor air BTEX.

• 한국대기환경학회지
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• 제6권1호
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• pp.1-10
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• 1990

The purpose of the study was to analyze air quality in underground shopping centers using pattern recognition methods. In order to perform this, the concentraion of air pollutants such as $CO, NO_2, NO_x, SO_2$, and particulate matters was measured at the 11 different shopping centers in Seoul metropolitan area and the total of 47 samples were obtained at random based on the size of shopping centers. To introduce a new concept of the "average concentration" for the indoor air quality analyses, the various multivariate statistical analyses have been studied. Thus, a cluster analysis was applied to separate the samples into pseudo-patterns and a disjoint principal component analysis was used to generate homogeneous patterns after removing outliers from the pseudo-patterns. The 6 homogeneous patterns were then obtained as follows:the first pattern was a group of clean sites;the second a group of sites having high dust concentration;the third a group of sites having high dust and $NO_x$ concentration;the fourth a group of sites having low dust and $SO_2$ concentraion and high CO concentration;the fifth a group of sites having high $NO_2 and SO_2$ concentration;and the final a group of miscellaneous sites. Thus, the average concentration could be estimated for each pattern.h pattern.

• 문화기술의 융합
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• 제4권1호
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• pp.325-329
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• 2018

실내 거주공간에는 건축 자재, 환기, 조리 등으로 인하여 많은 오염물질이 발생한다. 이중 미세먼지는 1급 발암물질로 인체에 매우 유해한 물질이며, 주로 조리시에 가장 많이 발생한다. 따라서 실내공기질을 잘 관리하기 위해서는 조리시 발생하는 미세먼지의 농도와 환기방법과의 관계를 평가할 필요가 있다. 이에 본 연구에서는 음식물의 종류 및 환기방법에 따른 미세먼지(PM2.5)의 농도변화를 측정하고 분석하여, 주방 조리시 발생하는 미세먼지의 관리방안을 제시하고자 하였다.

• 원예과학기술지
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• 제33권5호
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• pp.751-762
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• 2015

본 연구는 평면형 바이오필터를 설계하여 제작하고 이 바이오필터에 디펜바키아(Dieffenbachia amoena 'Marianne')의 식재 여부에 따라 환기 용량을 제어할 수 있는 토양 수분 안정화 정도를 측정하고 미세먼지, 휘발성 유기화합물 및 포름알데히드(HCHO)와 같은 실내공기 오염물질에 대한 바이오필터의 제거율을 비교하였다. 실험 결과 디펜바키아의 식재 여부에 관계없이 모두 일정한 상대습도, 온도 및 토양 수분 함량을 나타내었고 이 바이오필터에 식재한 디펜바키아도 정상적으로 생육하였다. 바이오필터에 의한 미세먼지 제거율을 보면, 미세먼지(PM10)와 초미세먼지(PM2.5)의 입자 수는 토양만 있는 경우 각각 30%와 2% 이상 제거되었고, 디펜바키아를 식재한 경우도 각각 40%와 4% 이상 제거되었다. 미세먼지(PM10) 무게에 따른 제거율은 토양만 있는 경우 4% 이상, 디펜바키아를 식재한 경우 20% 이상으로 나타났다. 토양만 채운 바이오필터는 xylene, ethylbenzene, toluene, total volatile organic compounds(T-VOCs)를 63% 이상 제거하였으나 benzene은 22% 이상, HCHO는 38% 이상을 제거하였다. 디펜바키아를 식재한 바이오필터는 xylene, ethylbenzene, toluene, T-VOCs를 72% 이상 제거하였고 benzene과 HCHO도 39% 이상 제거하였다. 따라서 식물과 바이오 필터를 결합한 시스템은 미세먼지의 제거보다 휘발성 유기 화합물의 제거에 대한 효과가 더 높은 것으로 나타났다. 본 연구에서 제작한 평면형 바이오필터는 실내 공기질 정화에 매우 효과가 있는 것으로 나타났으며, 식물과 바이오필터를 결합하였을 때 그 효과는 더욱 큰 것으로 확인하였다.

• 보존과학연구
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• 통권30호
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• pp.47-61
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• 2009

Cultural heritages are affected by various environmental factors. Main factors are temperature, humidity, light and indoor air pollutants such as ozone, nitrogen oxides. Especially humidity condition is very important. Low humidity condition can cause contraction and high humidity condition can lead to growth of microorganism. This study is conducted to appraise an applicability of the Humidity Indicator which is one of the simple method for humidity control. The Humidity Indicator shows the humidity conditions through color change. Therefore, photometer was used to correctly measure the color change of Humidity Indicator. As a result of lab test, Humidity Indicators was stabilized after one hour from en exposure in a certain humidity condition and the indicators indicated clear correlations between color changes of Humidity Indicators and humidity conditions. Some Humidity Indicators which had been selected through the lab tests were applied to preservation facilities of cultural heritages and the indicators indicated closed correlations with humidity conditions in indoor of facilities.

• 대한임상검사과학회지
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• 제41권3호
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• pp.105-110
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• 2009

Yellow sand (or Asian dust) occurs mainly in spring in East Asia. Yellow sand from China and its surrounding regions transports air pollutants, such as aerosols, ozone, and heavy metals. The outdoor workers are frequently exposed to heavy metals during yellow sand phenomenon. This study was carried out to investigate the heavy metal levels in blood among 75 outdoor workers (exposed group) and 86 indoor workers (controled group) in Gyeonggi province from March 2008 to May 2009. Heavy metal levels in blood were analyzed by atomic absorption spectrophotometer. Mean blood lead levels in exposed group and controled group were $5.19{\pm}1.64{\mu}g/dL$, $4.24{\pm}1.34{\mu}g/dL$, respectively. Mean blood cadmium levels in exposed group and controled group were $1.28{\pm}0.89{\mu}g/dL$, $0.90{\pm}0.59{\mu}g/dL$, respectively. Lead and Cadmium levels in blood of exposed group were significantly higher than those of controled group. In the comparison of smoking status, lead and cadmium levels of smokers were significantly higher than those of non-smokers. In conclusion, the heavy metal levels of outdoor workers were significantly higher than those of indoor workers. And smoking was hazardous factor to elevate heavy metal levels in blood.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.613-618
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• 2011

More than 7 million persons use Seoul Metropolitan Subways (SMS) everyday and the number has been in increasing trend. With the increasing trend of concerns on indoor air quality(IAQ), the management of IAQ has become an important issue, especially in case of subway operators, because most of subway lines are placed underground with poor ventilation condition. The ultimate object of study develop independent cleaning device that reduce efficient fine particle and $CO_2$. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. Two layered electrically pre-charged filters were used for removing particulate matters and gas absorbers are packed between two layer filters for removing gases pollutants such $CO_2$, VOCs and HCHO. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. SCAP prototype is producted as all in one method which decrease fine dust, $CO_2$ and noxious gas. and basic test carry out with quantity of wind, a gap of pressure, sampling efficiency.

• 설비공학논문집
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• 제18권6호
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• pp.486-492
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• 2006

In this research, IAQ is measured to evaluate the emission performance of VOCs in three new apartment houses finished by totally EFMs (Environmental Friendly Material), partially installed EFMs and general materials. Among various VOCs, Target pollutants for the IAQ measurement are benzene, ethylbenzene, toluene, xylene, 1,4-Dichlorobenzene and formaldehyde. The measurement is conducted one day after each interior finishing material is worked over by construction schedule. The result of this research concluded that (1) Except toluene, the concentration levels of each pollutant did not exceed the national IAQ standards in all test residences, (2) As the interior finishing work schedule, A toluene level peaked when the furniture installing was ended. (3) The toluene concentration level of the house installed general interior materials as the non-EFMs furniture was one and half higher than other houses. Consequently, installing. the furniture made by EFMs is one of effective methods to improve the IAQ for new apartment houses.

• 설비공학논문집
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• 제24권2호
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• pp.136-141
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• 2012

Performance improvement of local exhaust system used in toilet and cooking place are main concern in a field of ventilation. In Korea, There are many high riser residential apartments in recent years. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser building depends on stack effect. This study investigates on the performance improvement of terminal device, roof fan, of vertical spiral duct used in high riser residential apartments. This paper focuses mainly on the effect of accessories, number or shape of blades, composed of roof fan with function of exhaust air volume of toilet and cooking place. Roof fan with 10 blades is observed at optimum exhaust performance in this study.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1652-1655
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• 2008

Indoor air quality (IAQ) of subway becomes a key issue as the IAQ guidelines for public transportation published. There are two major sources regarding IAQ of subway; One is the sources coming from outdoor air and the other is sources of inside. Particulate matters smaller than 10 micrometer (PM10) and carbon dioxide ($CO_2$) are recognized as the one of the most severe pollutants in Korea. The source of PM10 is mainly coming from outdoor air, however, the source of $CO_2$ is coming from passengers exhaust. According to the guidelines, the level of $CO_2$ should be lower than 2500ppm for normal operating time and lower than 3500ppm for rush hour. In order to satisfy these guidelines, the volume of mechanical ventilation should be increase which consumes extra energy for heating or cooling. Therefore, the optimum volume of mechanical ventilation should be calculated for energy saving. In this study, we measured the natural ventilation rate by door-opening which can reduce the load of mechanical ventilation. The $CO_2$ generator and sensors were used to measure the change of $CO_2$ by periodic door-opening of subway.