• Journal of the Korean Regional Science Association
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• v.36 no.2
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• pp.3-12
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• 2020

Recently, metropolitanization and suburbization have been occurring mainly in large cities, and spatial miss-match between residential and employment areas has increased. Spatial miss-match is different in the metropolitan cities and other metropolitan cities in Korea. Seoul and other metropolitan cities have grown to become centers of business functions, while other metropolitan cities have been transformed into residential function centers. Accordingly, The reverse commuting phenomenon is occurring in the rural metropolitan. The reverse commuting phenomenon limits the employment opportunities of specific classes among urban residents, and cause various problems such as environmental pollution and traffic congestion. Therefore, many studies on spatial mismatch and reverse commuting have been conducted, but a number of studies have been conducted on the Seoul metropolitan area, and research on other metropolitan areas is insufficient. The purpose of this study is to analyze the cause of the commuting phenomenon in the metropolitan area of the non-metropolitan area by considering spatial mismatch and understanding the reverse commutation situation in the local metropolitan area. This study is analyzed by a multi-level model and suggests the need for management of industrial location and expansion of residence in suburban.

• Natural Product Sciences
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• v.17 no.1
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• pp.38-44
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• 2011

The quality inspections items such as loss on drying, total ash, and acid-insoluble ash contents in herbal medicines, have a correlation with external sources of pollution, but are not themselves hazardous factors. Z-scores for standard normal distribution were used to investigate herbal medicines requiring quality control, which exceeds the regulatory limits of quality inspection. In total, 7,773 samples were analyzed based on plant parts. For the loss on drying, the numbers of items of herbal medicines requiring quality control are like these; 15 items for above-ground parts and 5 items for underground parts. For the total ash, 21 items for above-ground parts and 4 items for underground parts. For the acid-insoluble ash, 8 items for above-ground parts and 1 item for underground parts.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.262-267
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• 2006

DBPs and T&O(taste-and-odor) compounds in drinking water is one of main source to deteriorate water quality. So, these compounds can cause adverse health effects and result in many consumer complaints aesthetically. This experiments carried out to investigate the effect of boiling water on DBPs and T&O compounds in the tap water. THMs and TCM concentration were reduced by 91.3%, 88.9% after 5 min of boiling, respectively. It is certainly, resulted from volatilization of TCM. TCAA concentration decreased when the water was boiled, too. By contrast, the concentration of DCAA was increased with duration time from boiling-point. The reduction of TCAA from the boiled water can be attributed to chemical transformation like decarboxylation. T&O compounds such as geosmin and 2-MIB was effectively removed by boiling of water, resulting in the removal efficiency of 97.1%, 94.4% after 5 min of boiling, respectively.

• Natural Product Sciences
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• v.12 no.3
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• pp.166-173
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• 2006

Silymarin is an antihepatotoxic substance isolated from the fruits of silybum mariamum. Possibly due to their antioxidant and membrane stabilizing properties, the compounds was shown to protect various organs and cells against a number of insults (Kvasnicka et al., 2003). Among the main silymarin components, [silybin($SB_A,\;SB_B$, isosilybin ($ISB_A,\;ISB_B$) silydianin (SD) and silychristin (SC)], silybin is the major pharmacologically active compound. Korean Pharmaceutical Codex (2nd ed.) describes silybin as the main substance of Cardus Marianus extract as supportive treatment of chronic inflammatory liver disorders. The aim of this work was to analyze silybin from various preparations containing cardus marianus extract, nicotinamide, and riboflavin (CNR). Nine commercial products were tested using reversed-phase HPLC-PDA assay. The limits of detection and quantification were $0.2\;{mu}g/ml$ and $1\;{mu}g/ml$, respectively. Calibration curve showed a good linearity ($r^2$=1.00000) in the range of $1{\sim}500\;{\mu}g/ml$ of silybin standard solutions.

• Korean Journal of Pharmacognosy
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• v.32 no.3 s.126
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• pp.200-211
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• 2001

This study was carried out to determine the 11 organochlorine, 7 organophosphorus residual pesticides in 251 crude drugs. These residual pesticides in herbal drugs were extracted with acetonitrile and the extracts were cleaned up via LC-florisil solid phase extraction column. The prepared samples were assayed for pesticide residues using GC-ECD, NPD with capillary column and identified by GC-MSD. Recoveries were $63.9{\sim}111.5%$ in the organochlorine pesticides and $69.8{\sim}92.4%$ in the organophosphorus pesticides, and detection limits were $0.001{\sim}0.65\;ppm$ in the organochlorine pesticides and $0.0009{\sim}0.0074\;ppm$ in the organophosphorus pesticides. Pesticide residues were detected in 9 cases.

• Corrosion Science and Technology
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• v.11 no.2
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• pp.56-64
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• 2012

Factors affecting corrosion of stainless steels such as pH, oxidation and redox potential (ORP), soil resistivity, water content of soil, chloride ion concentration, bacteria activity, and corrosion potential have been investigated using soil analysis, bacterial analysis, surfacial analysis, and analysis of corrosion potentials of several stainless steels buried in 8 sites of Seoul metropolitan for one year. Corrosion potential was affected by occurrance of corrosion as well as bacteria activity but the behavior of corrosion potential with time is different depending on occurrance of corrosion and bacteria activity. The main factor affecting corrosion of stainless steels in soil is level of chloride ion concentration which is also a main factor affecting corrosion of stainless steels in chloride containing drinkable water. Furthermore, guideline of stainless steels in drinkable water is concluded to be applicable to that in soil by the results from surfacial analysis.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.8-13
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• 2016

This study investigated the removal of a radioactive cesium ($Cs^+$) in the water at the water treatment processes. Since cesium is mostly present as the $Cs^+$ ion state in water, it is not removed by sand filtration, and coagulation with polyaluminum chloride (PACl), powdered activated carbon (PAC) and mixture of PACl and PAC. However, it is known that the removal rate of cesium increases as the turbidity increases in raw water. As the turbidity was adjusted by 74 NTU and 103 NTU using the surrounding solids near G-water intake and yellow soils, removal rate of cesium was about 56% and 51%, respectively. In case of a GAC filtration with supernatants after jar-mixing/setting was conducted, 80% of cesium is approximately eliminated. The experimental results show that it is efficient to get rid of cesium when the turbidity of the raw water is more than 80 NTU. In case of a GAC filtration, about 60% of cesium is removed and it is considered by the effect of adsorption. Cesium is not eliminated by microfiltration membrane while about 75% of cesium is removed by reverse osmosis.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.1-6
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• 2009

• Journal of Agricultural Extension & Community Development
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• v.11 no.1
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• pp.139-159
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• 2004

Since 1990s, the countrysides in Seoul Metropolitan Area have been exposed to the unprecedented forces like developing telecommunication technology, the boom of exurban housing, increasing concern about food quality. While these new forces are restructuring the social and spatial pattern of countryside, a legal regulation can be assumed as exerting an overarching moulding power. This paper shows how the legal regulation works in the restructuring rurality.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.1-5
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• 2011

We surveyed the citizens opinion about springs in Seoul for two years from 2008 to 2009. It was found that spring water was mostly used by citizens older than 50, and that 29.5% of citizens used purified tap water as drinking water, 27.2% of them used boiled tap water, 21.1% of them used spring water, and 12.1% of them used bottled water. Citizens who store spring water more than a day are 76.7%. Although many citizens (70.3%) knew that water quality had been tested, 40% of them didn't care about checking the certificate of water quality analysis. Once recognized that the spring water was unfit for drinking exceeded standard of drinking water, 85% of citizens would rather not use the spring water.