• Journal of Korean Society for Atmospheric Environment
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• v.21 no.5
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• pp.515-524
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• 2005

In this study, the concentrations of major reduced sulfur compounds (RSC: $H_{2}S,\;CH_{3}SH$, DMS, $CS_2$ and DMDS) were determined from various emission sources of individual companies located within the Ban Wal industrial complex of Ansan city, Korea. We investigated the emission concentration levels of RSC from a total of 47 individual companies during June 2004 to January 2005. The results of our study indicate that the emission concentration levels of RSC vary in a highly complicated manner in relation with industrial sectors and emission source types. It was found that both $H_{2}S\;and\;CH_{3}SH$ make the highest contribution to nuisance in the leather industry. Likewise, DMS showed its maximum contribution from food production sector, while DMDS for chemical production sector. When the emission data sets were compared between different emission sources, regardless of industrial types or activities, $H_{2}S\;and\;CH_{3}SH$ concentrations were seen most significant at waste treatment process. The overall results of our study suggest that the emission concentrations of sulfur compounds can be used to distinguish different sources of malodor released by different industrial activities.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.238-240
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• 2005

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.209-220
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• 2006

In this study, the distribution patterns of major odorous compounds in ambient air were investigated in the areas surrounding the Ban-Wall industrial complex of Ansan, Korea (Aug. 2004 to Sep. 2005). The results indicated the environmental significance of several major odorous compounds which include carbonyl compounds, reduced sulfur compounds (RSC), and volatile organic compounds (VOC). When the results were compared on a diurnal basis, the afternoon time concentration of most odorous compounds were notably higher than their morning time counterparts. It also indicated that the odor concentrations differed greatly, in terms of spatial grouping scheme of data sets, such as between industrial area and non-industrial area. The comparison of spatial patterns indicated that the concentrations of most of the compounds at the industrial area were maintained at high concentration levels, compared to the surrounding areas. The overall results of this study thus suggest that the distribution of odorous compounds in a large industrial complex can exhibit a unique pattern of their own.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.10a
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• pp.56-58
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• 2006

• Journal of the Korean GEO-environmental Society
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• v.18 no.11
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• pp.19-26
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• 2017

When narrowly excavated in the urban area, the wall of backfill space is not only symmetrical but also asymmetrical. In this case, the horizontal stress induced by backfilling depends mostly on the wall asymmetry and the wall friction angle. Therefore, in this study, the model test in the laboratory was conducted to investigate horizontal earth pressure with depth considering various boundary conditions such as base width, wall friction, relative density of backfill, and wall angle. As the wall is smoother and wall angle is lower from the bottom, the results showed higher the horizontal stresses due to the increase of vertical stresses.

• Korean Journal of Head & Neck Oncology
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• v.34 no.1
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• pp.29-32
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• 2018

The parathyroid glands are usually located in the posterolateral area of the thyroid gland. Due to their embryologic origin, they are sometimes found in an ectopic position from the angle of the jaw to the mediastinum. However, their incidental detection in the hypopharyngeal wall is rare. Herein, we report a case of an ectopic parathyroid gland found in the hypopharyngeal wall of a 39-year old woman with no known endocrine abnormality.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.110-124
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• 2007

In this study, the control efficiency of odorous compounds was measured from diverse control process units of 14 individual companies located within the Ban-Wall industrial complex of Ansan city, Korea (January to July 2005), To quantify the control efficiency levels of major odorous compounds, we collected odor samples from both the front and rear side of 17 control process units ($N=17{\times}2=34$). If the control efficiency is compared for each of 32 compounds between different process units, wet scrubber (WS) was found to be the most effective unit in terms of the sum of pollutants showing the positive control signals. Although the WS system shows generally a good control pattern for VOC, it is not the case for most index odorous pollutants; only 3 out of 12 index compounds were found to show positive control efficiencies. The results of the study also indicated that the control efficiency differ greatly between different industrial sectors and/or control process types. In the case of leather industry, carbonyl compounds were found to exhibit the highest control efficiency with its values varying from 19 to 90%. On the other hand, in the case of metal production sector, VOC recorded the maximum control efficiency with values varying from 18 to 79%. According to this study, most air pollution control facilities operated in most companies show fairly poor control efficiencies for most malodor compounds. Hence, to obtain best control efficiency of odorous pollutant emission, acquisition of better information on source characteristics and establishment of effective control technologies are highly demanding.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.679-692
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• 2006

The carbonyl compounds in the atmosphere belong to one of the regulatory pollutants for the malodor control designated by the Korean Ministry of Environment(KMOE). In the present study, the emission concentration levels of carbonyl compounds were measured along with a number of criteria odor pollutants from a total of 47 individual companies(June 2004 to January 2005). The results of our study showed that a number of carbonyl compounds(such as formaldehyde, acetaldehyde, acetone, and butyraldehyde) maintained significantly high mean concentrations of 298 to 372 ppb. In contrast, other carbonyl compounds were low enough with the mean valves of 0.54 to 19.1 ppb. It was found that except for such industries as metal production or leather processing, their emissions were generally quite significant. If the measured values were evaluated in terms of malodor intensity, butyraldehyde appeared to be the most significant contributor to the malodor release. According to the measurements made in strong source areas, it can be concluded that several carbonyl compounds(acetaldehyde, propionaldehyde, butyraldehyde, isovaleraldehyde, and valeraldehyde) are useful enough to diagnose malodor release from those source areas. It should also be addressed that a number of carbonyl compounds added newly as the result of malodor control legislation were not sensitive enough to diagnose malodor release from such sources.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.3
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• pp.325-336
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• 2006

The presence of volatile organic compounds (VOC), produced and released from both anthropogenic and natural sources, can accelerate the degradation of air quality in the surrounding area. In this study, we investigated the emission concentrations of VOC based on a total of 115 sample analysis made from 47 companies (representing 17 types of industry) at the Ban Wall industrial complex (Jun. 2004 to Jan. 2005). Through a statistical analysis of these measurement data, we inspected the emission characteristics of VOC in relation with industrial type and processing unit. When these data were compared each other, toluene was found to record the highest value of 423 ppb followed by ethylbenzene (68.3 ppb), m, p-xylene (43.6 ppb), o-xylene (27.2 ppb), styrene (23.9 ppb), and benzene (16.4 pub). In addition, by converting these VOC concentration data into malodor intensity, we attempted to account for their distribution patterns in terms of relative contribution to the malodor formation. The results of odor intensity conversion generally indicated that the odor intensities of individual VOC do not exceed the degree of 1. When our VOC results were compared against other odorous compounds measured concurrently, the results were highly contrasting each other. Despite relative insignificance as odorous compounds, these VOCs are generally found ubiquitously and in abundant quantities in this strong source area.

• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.99-106
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• 2020

Man-made slope is inevitable to make a new road, which may result in environmental problems as well as collapse of slope. To prevent these problems, various methods such as geogrid reinforced retaining wall, precast concrete-panel retaining wall, and so on, have been introduced and developed. Among these methods, this paper presents the evaluation of field application of precast concrete-panel retaining wall attached to in-situ ground (so called top-down) compared to the conventional construction method of precast concrete-panel retaining wall (so called bottom-up) through the field test and numerical analysis. As a result, the safety factor of both methods in final stage is similar, however, top-down method guarantees the slope stability during the construction compared to bottom-up method.