• Journal of the Korean Geographical Society
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• v.32 no.2
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• pp.175-195
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• 1997

This study attempts to understand new immigrants' socio-economic adaptation by linking them with the restructuring economies in large US metropolitan areas. Selecting Los Angeles, New York, Chicago, and Atlanta, we examine the industrial distribution of employed Hispanic and Asian immigrant groups with respect to the industrial change experienced between 1980 and 1990, and residential concentration represented by higher location quotients. The findings are that new immigrant groups are employed in overall industrial sectors close to that of total population and their large residential concentrations are displayed near downtown as well as outlying areas. These suggest that new immigrant groups experience different socio-economic adaptation from those generalized in the previous European immigrants, concentrated in manufacturing sector and near downtown area. This study proposes that divergent economic restructuring across metropolitan areas and new immigrants' backgrounds should be considered for better understanding of immigrants' economic adaptation in the current economic restructuring and its spatial manifestation in the US contexts.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.23-33
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• 2006

The factor of air pollution in a large industrial city is not only manufactories but also, activities related to trucks. Sihwa National Industrial Complex is located in Siheung City; due to the industries, more diverse activities related to trucks occur in Siheung City than other cities. In particular, the new residential area in Siheung City is close to the industrial complex; so, the damage of this residential area is expected that it would be more serious and vulnerable than other areas. The aim of this study is to analyze influence of the air pollution by a truck in Siheung City. ISCST3 Model and Arc View program were used for this study and Siheung City was divided into 1,000 meter by 1,000 meter grid to analyze. Furthermore, this study suggested two reduction controls of air pollution in Siheung City, and analyzed the results from these reduction managements. The results of the present condition showed that residences located in north of Sihwa Industrial Complex are influenced by air pollution material. Furthermore, air pollution by trucks has affected on the residents which is near the road in Siheung City. Therefore, this study suggested two reduction controls by the Traffic System Management. The first alternative plan is setting the truck traffic limitation zone in the road that is located in south of resident areas and many trucks traffic. Next, the second alternative plan is setting freight truck way on the most traffic road to enter the industrial complex. The reduction effect of the first alternative is good on the residential area. And, the second alternate about freight truck way is divided passenger cars into trucks. Therefore, there are increase of average speed and decrease of average concentration, and spatial reduction effects found in wide areas.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.517-522
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• 2008

Ventilation rate and filter were selected to simultaneously satisfy indoor air quality and minimize energy consumption in residential housing. The concentrations of indoor particles were calculated using an adapted mass balance model for various ventilation airflow rates. To satisfy the guidelines for indoor concentrations of particles, the minimum ventilation rates of 1.0/h, 0.6/h and 0.4/h were required for MERV11, MERV13 and MERV14, respectively. And the fan power consumptions induced by ducts, a heat exchanger and a filter were calculated for various ventilation airflow rates. The increase in the ventilation rate caused a dramatic increase in the power consumption, but the filter performance did not have much of an effect on the fan power for ventilation airflow rates lower than 0.4/h. The use of the ventilation filter of MERV 14 was suggested at a ventilation rate of 0.4/h when the fan power consumptions were considered in addition to the indoor concentrations of particles and $CO_2$. The use of the MERV14 filter at a ventilation rate of 0.6/h could be more effective than the additional use of an indoor air cleaner when the residential housing unit was ventilated.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.517-525
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• 2009

We measured ambient concentrations of hazardous air pollutants such as volatile organic compounds (VOCs) and aldehydes in residential areas nearby small and medium scale shipbuilding companies. The VOC concentrations were higher during the normal operation periods than vacation at which almost all operations were shutdown. Concentrations of VOCs was higher, as the sampling site was nearer from shipbuilding companies. The major components of VOCs were m,p-xylene, ethylbenzene, o-xylene, toluene, and 1,3,5-trimethylbenzene which had been found as major VOC compounds emitted from painting processes of shipbuilding in the previous studies. The major components of aldehydes analyzed were benzaldehyde, acrolein, formaldehyde, and acetaldehyde. The concentration of aldehydes was highest at the furthest sampling point from shipbuilding companies because the formation of aldehyde compounds could be occurred by the secondary chemical reactions of VOCs. The results of this study shows a proper counterplan need to be established for the reduction of hazardous air pollutants emitted from small and medium scale shipping companies.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.418-425
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• 2013

Objective: This study was carried out for the purpose of identifying major substances contributing to the production of odor and evaluating the characteristic of odors. Methods: Complex odor and 17 odorous compounds were measured at 18 waste transfer stations located in Seoul. Results: The dilution ratio value of complex odor ranged from 4 to 30 times in the boundary layer of 18 waste transfer stations. At 6 measurement points among the 18 waste transfer stations, the dilution ratio values exceeded standards (15 times). When the results were evaluated in terms of their contribution to the formation of malodor, the patterns indicated that the highest concentration values in the residential waste disposal process were of i-valeraldehyde and acetaldehyde, while butyraldehyde and acetaldehyde accounted for a large proportion of odorous compounds from the waste recycling process. Conclusions: It was found that butyraldehyde and acetaldehyde were the primary compounds released from the food waste disposal process. Overall, aldehyde compounds were the greatest contributor to detectable odor intensity emitted at the waste transfer stations.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.731-734
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• 2009

KIER has been developed a compact and highly efficient fuel processor which is one of the key component of the residential PEM fuel cells system. The fuel processor uses methane steam reforming to convert natural gas to a mixture of water, hydrogen, carbon dioxide, carbon monoxide and unreacted methane. Then carbon monoxide is converted to carbon dioxide in water-gas-shift reactor and preferential oxidation reactor. A start-up time of the fuel processor is about 1h and CO concentration among the final product is maintained less than 5 vol. ppm. To achieve high thermal efficiency of 80% on a LHV basis, an optimal thermal network was designed. Internal heat exchange of the fuel processor is so efficient that the temperature of the reformed gas and the flue gas at the exit of the fuel processor remains less than $100^{\circ}C$. A compact design considering a mixing and distribution of the feed was applied to reduce the reactor volume. The current volume of the fuel processor is 17L with insulation.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.367-375
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• 2008

To characterize atmospheric particles in Cheonan area, 5 monitoring sites representing highway area, commercial area, residential area, and industrial areas were selected, and the mass concentrations of PM10 and PM2.5 were monitored for 14 days at each site during 2007. The daily average PM10 and PM2.5 concentrations were in the range from 18.5 to $140.9{\mu}g/m^3$ and 8.2 to $116.6{\mu}g/m^3$, respectively, showing the highest mean concentrations at the commercial area site and the lowest concentration at the residential area site. The daily average PM 10 concentrations at Shinan (Commercial area) and Bakseok (Industrial area) sites were exceeded the current National Standard for 1 and 2 days during the monitoring periods. The fractions of PM2.5 in PM10 were above 70% for all sites, indicating fine particles are the major constituent of atmospheric particles in Cheonan. The results indicate that PM10 concentrations in Cheonan are at the concerning level, and the control strategy for fine particles is necessary to address this issue.

• Journal of Environmental Science International
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• v.11 no.8
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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.

• Journal of Environmental Science International
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• v.25 no.11
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• pp.1555-1562
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• 2016

Concentrations of hydrogen sulfide in ambient air have been measured from January 2014 to June 2016 in a coastal area near the Ulsan National Industrial Complex. The measurement sites were 1 km, 2.6 km, 5.6 km, and 20 km away from a kraft pulp mill, which is located at the most southern edge of the complex. Concentrations above 0.4 ppb were monitored every 5 min and the highest concentration of the day was determined. From a total of 775 measurement days, hydrogen sulfide concentrations > 20 ppb were recorded on 36 and 38 days at the measurement site closest to the mill and the residential area 2.6 km away from the mill, respectively. At the site farthest from the mill, the concentrations were always 20 ppb lower than the malodor regulation for the residential area but sometimes higher than the odor recognition threshold for hydrogen sulfide. Although several emission sources of hydrogen sulfide have been published in the Pollutant Release and Transfer Register of Korea, the kraft pulp mill is considered to be the biggest contributor of atmospheric hydrogen sulfide in the southern coastal area of Ulsan.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.107-118
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• 2005

In this study, the concentrations of major odorous compounds including reduced sulfur compounds (OMS, CS$_2$, and DMDS) and aromatic VOC (benzene, toluene, xylene, etc.) were measured continuously using an on-line GC analytical system. Our measurements were made from a residential area of Ansan sity during about two week period of October, 2004. The highest mean concentrations of Sand VOC were found as 56.9 pbb of DMS and 21.7 ppb of toluene, respectively. The results of this study generally show that the pollution levels for both types of chemicals are significant relative to previous measurement results reported from comparable sites, if the results are compared simply in terms of the magnitude of the measured concentration data. Moreover, when the relative importance of different compounds is compared in terms of the odor strength, it indicated that the contribution of reduced S compounds may be much more important than that of VOC in the study area.