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        검색결과 20

        1.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to develop a system to reduce ultrafine dust using hygroscopic materials such as glycerin and propylene glycol. Prior to the development of an ultrafine dust reduction system, the moisture condensation efficiency of glycerin and propylene glycol was investigated based on relative humidity (RH). The results showed that when no substances (glycerin and propylene glycol) were added to a tedlar bag, the relative humidity and temperature remained constant. The moisture condensation efficiency of glycerin was 60%, and the time it took to reach 50% of the initial relative humidity was about 40minutes. In the case of propylene glycol, the moisture condensation efficiency was 75%, and the time it took to reach 50% of the initial relative humidity was about 10 minutes. When glycerin and propylene glycol mixture was added, the moisture condensation efficiency was 68% and it took 20 minutes to reach 50% of the initial relative humidity. These results suggest that hygroscopic materials such as glycerin and propylene glycol can actually condense moisture in the atmosphere. In addition, considering actual atmospheric conditions, the relative humidity was set to 60% and 40% or less, and the moisture condensation efficiency was measured. The results showed that the mixture of glycerin and propylene glycol yielded the highest condensation efficiencies, at 69% and 62%, respectively. Therefore, it is preferable to use a mixture of glycerin and propylene glycol to condense moisture in the range of relative humidity in the actual atmosphere.
        4,000원
        2.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to analyze the effects of 4 directions of wind, wind speed, year of construction of slate roofs, installation area and other factors on the concentration and size distribution of airborne fiber particles in farmhouses with a slate roof containing asbestos. Airborne fiber particle samples were collected from the air in six houses with a slate roof containing asbestos using a high flow rate pump (10 L/min) for 2 hours, three times a day with a different condition, 72 times in total. The airborne fiber particle concentrations were measured using a phase contrast microscope, and the size of fiber particles of 72 samples in total was estimated using the mean value of those in each sample measured at 100 with a field of view. The total average concentration of fiber particles collected from in the air in four directions of the targeted farmhouses was 2.83 fiber/L, and its maximum concentration was 5.75 fiber/L, which means that among all samples there was no place that exceeded 10 fiber/L, a recommended indoor air quality standard. The average size of the fiber particles was 11.55 μm, and the maximum size was 40 μm. A multiple regression analysis of factors affecting the concentration and size of fiber particles in the air collected from the farmhouses with a slate roof containing asbestos found that the closer to the main wind direction (p<0.001) and the faster the average wind speed (p<0.05), the fiber particles concentration became significantly higher. In this case, the coefficient of determination was 52.8%. It was also found that the wider the total area of the slate roof (p<0.001) and the slower the average wind speed (p<0.05), the longer the fiber particles; the coefficient of determination for this finding was 19.6%. The concentration of fiber particles in the air of farmhouses with a slate roof appeared to be the highest under the main wind direction, and became significantly higher as the wind speed became faster. This proved that fiber particles were leaked from the slate roof. The size of the fiber particles became significantly longer as the area of the slate roof became wider and the wind speed became slower.
        4,000원
        3.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Changes in land use and increase in urban energy consumption influence urban life. This study analyzed the characteristics and patterns of urban heat and presents management schemes to generate a comfortable and sustainable urban environment. The study aimed to demonstrate the positive effects of artificial ground greening on improving the microclimate through evapotranspiration using perennial herbs. We have designed a chamber that could control constant temperature and humidity, measure temperature reductions in each plant and changes in sensible heat and latent heat. This study identified Sedum kamtschaticum as the most effective plant in controlling temperature. At 22℃, 3.2℃ temperature reduction was observed, whereas four other plants showed a 1.5℃ reduction. At 25℃, 2.0℃ temperature reduction was observed. On the other hand, the use of Sedum sarmentosum resulted in the lowest effect. Zoysia japonica is the most commonly used ground covering plant, although the temperature reduction of Lysimachia nummularia was more effective at high temperature conditions. Sensible heat and latent heat were calculated to evaluate the thermal performance of energy. At a temperature >30℃, L. nummularia and S. sarmentosum emitted high latent heat. In this study, we analyzed the thermal performance of green roof perennial plants; in particular, we analyzed the evapotranspiration and temperature reduction of each plant. Since the substrate depth and types, plant species, and seasonal change may influence temperature reduction and latent heat of green roofs, further studies are necessary.
        4,000원
        4.
        2016.02 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to evaluate the performance of a tube and badge type NO2 passive air sampler. The principle of the method is a colorimetric reaction of NO2 with N-1-naphthylethylendiamine under acidic conditions. The sampling rates for the tube and badge type passive air samplers was determined 12.3 ± 4.4 mL/min and 27.3 ± 4.9 mL/min, respectively, as obtained from the slope of the linear correlation between the NO2 mass collected by the passive air sampler and the NO2 concentration with the NO2 analyzer. The tube and badge type passive air sampler were moderately correlated with a correlation coefficient of 0.9112. The measurement for the precision and accuracy of the passive air sampling was carried out with duplicate measurement of passive air samplers. The passive air sampler had good precision and accuracy for measuring NO2 in atmosphere. A good correlation was observed between the passive air sampler and the NO2 analyzer with a coefficient of determination of 0.9153 (tube type) and 0.9514 (badge type). This passive air sampler would be suitable for the NO2 concentration monitoring in atmosphere.
        4,000원
        5.
        2012.02 구독 인증기관 무료, 개인회원 유료
        It was investigated the state information for the atmospheric conditions around Dang-jin industrial complex in Chungnam area may be polluted by the constructing steel industrial complex. It is aimed at characterization of the fine particulate matter and other air pollutants involved in it. Samples were collected two sites for monitoring point representing steel industrial complex and one site which is placed a remote and secluded from this industrial complex, and the concentration of PM10, heavy metals, and ion components were analyzed. As a results, PM10 average concentration was 64.6㎍/㎥ for the adjacent site before Hyundai Steel Company, 70.5㎍/㎥ in Bugok immigration settlement complex, and 56.5㎍/㎥ for Jeonggok-ri contrastive point. The distribution of heavy metals was detected as very low level for all sampling points. According to the result of statistical evaluation for the heavy metal analysis, variation range of Cu, Mn, Ca, Fe, and Mg were significant higher than others. Also, the seasonal concentration change trend of heavy metals was remarkable strong in spring and low in summer because of instable meteorological phenomena such as yellow dust happened in spring. Monthly changing pattern of a sulphate ion has kept unusually high level for summer period different other components. Relationship among PM10, heavy metal, and ion component were analyzed that high positive correlation coefficient for PM10 between Fe, Mn, Pb, Ca, Mg, Cd, Al in order and PM10 between NO3-, Cl- successively. Accordingly, it is suggested that a present atmospheric conditions of the surrounding area of Dang-jin steel industrial complex is considered to be good level. Although air pollutants in emissions from their complex were below the existing emission limit, it is regarded that the systematic and continuous research is needed to preserve clean air through atmospheric monitoring, source tracing research, and citizen's surveillance for the fine particulate matter.
        4,300원
        6.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the spatial and temporal distribution of odorants in ambient air was investigated at three measurement points in a University campus in Seoul city during a 15 day study period. The concentrations of 12 target analytes designated as malodor compounds by KMOE were measured through time. The highest mean concentration (in ppb unit) was found from NH₃(25.3) followed by styrene (0.51) > acetaldehyde (0.13) > H₂S, propionaldehyde (0.07) > butyraldehyde, isovaleraldehyde, and valeraldehyde (0.06) > DMDS (0.04) > TMA (0.03) > CH₃SH and DMS (0.01). Comparison of odorant data showed fairly strong distinctions across diurnal period, while differences in concentration levels were not clear enough between different sampling locations. The results of correlation analysis showed that the concentrations of DMS and NH₃ were strongly correlated with relative humidity. In addition, most of reduced sulfur compounds (RSC) exhibited strong correlations with each other. When the odorant concentrations were converted into odor intensity, the values were typically found below the odor degree of 1. The odor intensity, if assessed by the maximum values of each compound, were generally in between 1~2 odor degree level (e.g., H₂S, CH₃SH, DMDS, acetaldehyde, and TMA). The results of this study thus show that most odorant species occurred below the threshold value at clean space like a University campus. Hence, more efforts are desirable toward the development of the analytical technique at various concentration levels.
        4,800원
        7.
        2006.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        In recent European telecommunication base transceiver stations(BTS), a membrane laminated air filter is reported to replace a heat exchanger in order to cool internal digital units of BTS. The concept of using the air filter is for the direct ambient cooling (DAC) of BTS without heat loss generally found in the heat exchanger type BTS. In the present study, a performance evaluation experiment was conducted to investigate the pressure drop characteristics with dust loading and the particle collection efficiency of the air filter for the DAC of BTS. Finally, the long term operation lifetime of the air filter for BTS was suggested with a given fan rotation speed.
        4,000원
        9.
        2001.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2000년 춘계에 한국 농촌지역인 충남 서산에서 대기부유분진(SPM)과 곰팡이포자의 관계에 대해 조사하였다. 부유분진의 농도는 1차 황사기간(3월 23-24일)에 199.8μg m-3, 2차 황사기간(4월 7-9일)에 249.4μg m-3, 비황사기간(5월 12-6일)에 98.9μg m-3으로 각각 나타났다. 2회의 황사기간들간에 부유분진 농도는 차이를 보였지만 5μm 정도의 입경 크기를
        4,000원
        10.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        참외 과실부위 송풍이 칼슘흡수와 발효과 발생에 미치는 영향을 구명하기 위하여, 풍속 0.3m/sec로 10시부터 13시까지 1일 3시간 과실부위에 송풍을 하였다. 송풍은 착과 10일후, 20일후, 30일 후부터 수확까지 송풍처리구와 무송풍구로 나누어 비교한 결과, 과중은 착과 30일후 송풍처리에서 가장 무거웠으며, 과육두께는 착과 30일후 송풍구에서 가장 두꺼웠다. 과실의 경도는 착과 10일후 송풍구에서 가장 높았으며, 과육 및 태좌의 당도는 착과 20일 후 송풍 처리에서 가장 높았다. 과실의 L값은 착과 10일후 송풍구, a값 및 Y. I값은 착과 30일후 송풍구에서 좋아 무송풍에 비하여 송풍 처리에서 과실의 착색이 우수하였다. 과육 및 태좌의 Ca 함량은 송풍처리에 비하여 무송풍처리에서 많았으나, 발효과 발생은 송풍처리구에서 적었다. 특히 착과 20일후 송풍처리구에서 발효과율 및 기형과율의 발생이 적었고 상품과율은 증가하였다.
        4,000원
        11.
        2023.06 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the characteristics of Volatile Organic Compounds(VOCs) emission from painting and printing facilities in the Pyeongdong industrial complex in Gwangju. In addition, the objective was to understand the distribution characteristics of VOCs in the ambient air in industrial complexes affected by painting and printing facilities. The painting facility mainly emitted toluene, acetone, butyl acetate, 4-methyl-2-pentanone, ethyl acetate, 1-butanol, methyl ethyl ketone, m,p-xylene, o-xylene, 4-ethyltoluene, ethylbenzene, 3-ethyltoluene, and 1,2,4-trimethylbenzene. The main emission components in printing facilities were methyl ketone, ethyl acetate, acetone, 2-propanol, toluene, heptane, and butyl acetate. Ethyl acetate, toluene, 2-butanone, acetone, butyl acetate, 2-propanol, xylenes, and 4-methyl-2-pentanone were detected in the ambient air of the Pyeongdong industrial complex, consistent with the VOCs emitted by painting and printing facilities. The average concentration of seasonal TVOCs followed an order of winter > fall > spring > summer, whereas the concentrations of daytime and nighttime TVOCs were generally higher at night than those during the day, and the wind speed was greater during the day than it was at night. Based on a factor analysis of VOCs in the ambient air of Pyeongdong industrial complex, it is considered that organic solvents used in coating, printing, and electronics manufacturing facilities, as well as diesel vehicle emissions played a major role.
        12.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and waterof the western and southern regions of Korea. The samples from the western region were collected from Anmyeon Island, and the samples from the southern region were collected from Kimhae and Busan. The concentration of HCH isomers in atmosphere showed the pattern of α-HCH>γ-HCH>ß-HCH. The regions with high HCH concentration in the atmosphere are the regions that have been highly exposed to HCH used in the past, and the areas that have been influenced by the long range transport. The HCH that persists in the soil, water and sediment evaporates into the atmosphere, showing the characteristics of Air-Surface exchange. When the regional concentration distributions arecompared, the concentration of HCH was higher in the atmosphere of a plain and the cities near the plain, than the urban areas. In this study, the ratio of α/γ-HCH was used as an indicator for estimating the source of Technical HCH and Lindane. According to the result, the contribution of Lindane was high in Kimhae plain and Kimhae urban areas. However, in Busan, the contribution of Technical HCH was higher than Lindane. In case of Anmyeon Island, the western region of Korea had high contribution from Tehcnical HCH. In soil and sediment, ß-HCH was dominant. In water, γ-HCH was dominant among other isomers. Such results are due to γ-HCH inLindane. Furthermore, the source of γ-HCH in urban areas is assumed to be the use of medicine, medical supplies and other living supplies. Based on the results of this study, the management of HCH, a newly list up emerging POPs, should be strengthened by further research on sources, fate, persistency, accumulation and exposures and etc. to the risk assessments.
        13.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        This study aims to monitor the variation of concentration of PCDD/DFs between the gaseous phase-particulate phases in the ambient air of urban area in Korea. This monitoring is evaluated by using the Junge-Pankow model and the Koa absorption model with the application of the Octanol-air partition coefficient. In this study, the ambient air samples were analyzed according to each congener group of the PCDD/DFs by HRGC/HRMS, which have been investigated for the past 5 years. In the results, the annual variation in the concentration level of ∑PCDD/DFs in TSP was increased from 1588 fg/㎥ in 1998 to 5123 fg/㎥ in 2002, and from 31 fg I-TEQ/㎥ to 94 fg I-TEQ/㎥ in the ∑I-TEQ. In the case of PUF of gaseous phase sample, their variation was increased from 1615 fg/㎥ in 1998 to 2237 fg/㎥ in 2002, and in the ∑I-TEQ from 12 fg I-TEQ/㎥ to 17 fg I-TEQ/㎥. The relative coefficient between the gas phase concentration of PCDD/DFs and the temperature was a value of 0.744; the contributive rate of the temperature to the gaseous phase concentration was 0.554. According to the results, the pattern of the coefficient of distribution based on log PL0 is similar to the ambient air of the urban areas.
        14.
        2007.08 KCI 등재 서비스 종료(열람 제한)
        This study assessed the characteristics of emission and cell toxicology of Methylethylketone(MEK) in ambient air of industrial area. MEK is produced by the oxidation of sec-butyl alcohol and used as the solvent for making ink, printing, coating of film, bonding material and drug extraction. The MEK concentrations in the ambient-air of industrial area in Gimhae City was detected in the range of 25.4~1,580 ㎍/㎥ with an average 297.4 ㎍/㎥. The concentration of MEK showed a descending tendency from April to August followed by its increased tendency since then. The effects of MEK on the human lung cancer A549 cells was examined by the generation of Reactive Oxygen Species(ROS) and cytotoxicity. The range of MEK concentration detected in the area induced ROS generation affecting the oxidation state with a little effects on the viability of the cells.
        15.
        2007.04 KCI 등재 서비스 종료(열람 제한)
        This study assessed the characteristic of BTEX (Benzene, Toluene, Ethylbenzene, Xylene) concentration ratios of industrial emission sources and the neighborhoods of industrial area, fuel such as gasoline, light oil, LPG, and similar gasoline, and ambient air in Daegu. The BTEX in aromatic compounds was the most abundant VOC in Daegu. The BTEX ratios were (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area, (2.6:11.3:1.0:1.2) for residential area, (2.2:11.0:1.0:1.6) for commercial area, (1.0:14.9:1.0:1.3) for industrial area, and (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area. Average BTEX ratios in Daegu were B/T ratio (0.1), B/EB ratio (1.5), B/X ratio (1.1), T/EB ratio (12.6), T/X ratio(10), EB/X ratio (0.7). Expecially, B/T ratio in Daegu was similar as the other cities, Bangkok, Manila, and Hongkong. Comparing other cities with B/T ratio, the main sources of VOC were vehicular exhaust and emission of industrial facilities. Furthermore, BTEX correlation were evaluated at the emission sources and regional areas. Results showed that correlation coefficient values of emission sources, fuels and neighborhood of industry were significant magnitude above 0.65(p<0.01). Also, there showed highly significant correlations among BTEX. Calculated correlation coefficients of ambient air sampling sites were 0.61~0.954 for commercial /residential area and 0.613~0.998 for industrial area. However, they showed different correlation between commercial/residental area and industrial area. It implied that the emission sources were different from each area.
        16.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        This study focuses on the measurement of airborne Volatile Organic Compounds (VOCs) in the Kumi electronic industrial complex during the time periods of August and September, 2002 and January and February, 2003. This study was based on the US-EPA method TO-14 while the VOCs were analyzed with GC/MSD. The toluene level revealed high concentration at all measurement sites. The areal rank of average concentrations of VOCs is as follows : industry1>industry2>urban>middle>residential. Concentrations of VOCs in Kumi electronic industrial ones were generally higher than at Yeochon and Ulsan industrial complexes. Dichloromethane and trichloroethylene, which are used as a cleaner in the process of electronic industries, were observed 4 to 8 times higher than those of other areas. Among the aromatic compounds, toluene showed the highest level, while the concentrations of dichloromethane and trichloroethylene were higher than those of other halogen compounds. In Kumi, toluene, trichloroethylene, and dichloromethane were confirmed as the major compounds of VOCs by this research.
        17.
        2003.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to estimate the air quality of subway stations having underground platforms in Busan Metropolitan City, from September to November 2000, over seven times. The places of the investigation include Yonsan-dong station, Somyon station, Busan station, Nampo-dong station, and Dusil station. Samplings were conducted at three points in each station, i.e. gates, ticket gates, and platforms. CO, NO, NO2, and O3 were the main components of air for this analysis. In order to more fully understand station environments, we also measured an air temperature at each point. The results showed that the O3 average concentration of Yonsan-dong station was higher than others with 38~51ppb. The average concentration of NO was high at the ticket gate and platform at Somyon station (119ppb, 122ppb) and Nampo-dong station (102ppb, 100ppb). These results show that the air pollution of stations with underground shopping malls were higher than others. At Somyon station having a junction station, NO and NO2 concentration levels of platform-2 (noncrowded) were higher than platform-1 (crowded). This is most likely due to the accumulation of air pollutants and inadequate ventilation systems. To find the relationship of the indoor (platform) and outdoor (gate), we analyzed the I/O ratio. The averages of CO and O3 were both higher than one: 1.16 and 1.82, respectively. In the correlations between each material and the others, NO vs NO2 was the highest with R=0.63. In the correlations between indoor and outdoor, O3 was the highest with R=0.64.
        18.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to quantitatively determine the indoor infiltration of pollutants of outdoor origin. The relationship between indoor and outdoor air is dependent, to a large extent, on the rate of air exchange between these two environments. Mean indoor/outdoor ratios measured from this study were: 0.70 for HNO_3; 1.60 for HNO_2; 0.56 for SO_2; 1.30 for NH_3; 0.96 for PM_2.5(d_p<2.5μm); 0.89 for SO_4^2-; 0.87 for NO_3^- and 0.79 for NH_4^+. Mean indoor concentrations for PM_2.5, SO_4^2-, HNO_3, NO_3^- and NH_4^+ were similar to outdoor levels. Indoor HNO_2 and NH_3 values were higher than outdoors. However, the indoor level of SO_2 was lower than ambient level.
        19.
        1996.08 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate the level of atmospheric heavy metals and the relationship of that concentration with weather conditions. This research monitored the concentration of Total Suspended Particulates (TSP) at every three hours by using High Volume Air Sampler from December 24th, of 1995 to Febuary 20th, 1996 in Kimhae area, which recently became a rapidly growing residential and industrial sitc. The items such as air-temperature, relative humidity, radition, wind speed, and wind direction were monitored by using Atmospheric Weather System at the same time. From the collected TSP, the concentration of heavy metals were analyzed by using the Atomic Absorption Spcetrophotometry. The mean concentration of TSP was 110.4 ㎍/㎥, and the mean concentration of lead (Pb), copper (Cu), chromium (Cr), manganese (Mn), cadmium (Cd), were 0.837 ㎍/㎥, 0.486 ㎍/㎥, 0.264 ㎍/㎥, 0.157 ㎍/㎥, 0.054 ㎍/㎥, respectively. Regarding daily variations, the concentration of TSP was highest in the morning (158.1 ㎍/㎥) followed by evening (119.4 ㎍/㎥) and afternoon (111.1 ㎍/㎥). The concentration of Pb and Mn was higher in the morning, and that of Cu, Cr and Cd was higher in the afternoon and the evening. Regarding the relationship between the concentration of pollutants and weather condition, the concentration TSP revealed positive correlation with temperature, humidity, wind speed, but negative correlation with radition (p<0.01). The concentration of Mn revealed positive correlation with temperature and humidity, but negative correlation with wind speed (p<0.01). And the the concentration of pollutants and weather condition revealed higher correlation within the same time period. In summary, the paralleled mornitoring of air conditions and weather condition should be recommended to get the correct informations concerning the pollution and to prevent the deterioration of air conditions.
        20.
        1995.03 KCI 등재 서비스 종료(열람 제한)
        To collect and evaluate an aerosol acidity (H^+) in ambient air, the cyclone/annular denuder/filter pack sampling system (ADS) was used. Aerosol acidity was collected in Chicago using the ADS for 81 12-hr samples divided in spring/summer/fall 1990 and winter 1991. This study illustrated that the ADS was suitable for measuring aerosol acidity. The 10^-5N HClO_4 extraction solution for pH determination provided more reliable scale than 10^-4N HClO_4. NH_3 should be removed prior to particle collection to accurately measure H^+ concentration on the filter. There was seasonal variation in aerosol acidity concentrations. Aerosols were more acidic in the summer. High correlations between SO_4^2- and NH_4^+, and between SO_4^2+ and H^+ were observed during the entire sampling period.