• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.120-122
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• 2001

This study was carried out to monitor suspected endocrine disrupting pesticides and industrial organic chemicals among circulated agricultural products in the north area of Seoul in 2001. Procymidone, vinclozolin, endosulfan, chlorothalonil, chloropyrifos and pendimetaline (pesticides) and butylated hydroxytoluene(industrial organic chemicals) were certified by GC-MS. Detected 6 pesticides were remained mostly in the green vegetables, spices and wild plants with $3\%$ detected. Butylated hydroxytoluene(industrial organic chemicals) used for green house cover stuffs was contained mostly in the green vegetables, spices and wild plants not in the fruits and cereals with $43\%$ detected. In the same agricultural products containing butylated hydroxy toluene showed same detection tendency with remaining endocrine disrupting pesticides.

• Korean Journal of Community Nutrition
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• v.2 no.1
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• pp.74-85
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• 1997

To investigate the perception and consumption of imported and organic produce, a survey was conducted using a questionnaire in Seoul, Taejon and Cheongju from February to March in 1995. The responses of 350 housewives were analyzed. Most of the subjects (96.8%) know an increase of imported produce, and 86.3% thought that imported produce was not safe. Ninety-two percent of the subjects preferred domestic produce to imported produce. The reasons were for the support of domestic farming (36.7%), hazardous chemicals in imported produce (25.0%), good taste (24.1%) and high quality of domestic produce (13.1%). Seventy-eight percent of the subjects had purchased imported produce. The reasons for purchase were cheap price (67.7%), high quality (16.2%), and good taste (5.4%). Imported produce were purchased in the following order ; fruits such as banana, kiwi, orange and grapefruit, seasonings such as garlic and sesame, vegetables such as onion, braken and green onion, and beans and grains such as soybean, red bean, and barley. Most of the subjects (94.3%) had been informed on organic produce. Among these, 45.2% obtained the information by TV or radio. However, son for purchase was low residual chemicals (64.6%). The reasons against purchase were inconvenience of purchase (42.3%), high price (25.4%), and disbelief of low residual chemicals (19.7%). Therefore, domestic produce should be good in quality and taste, and be safe without residual chemicals in order to compete with imported produce with cheap price. Informations on organic and imported produce should be provided to consumers, and the distribution system of organic produce should be improved for consumers convenience.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.45-50
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• 1999

Four cast iron pipe sections containing 3 styrene butadiene rubber (SBR) gaskets (1 joint and 2 end caps) were filled with water and maintained at approximately 40 psi internal pressure. The pipe sections were placed inside 16 gallon drums filled with initially clean sand. Three of the tanks were subsequently contaminated with gasoline, gasoline spiked with pyrene and naphthalene, and toluene. The forth tank served as a control. The water inside each pipe was monitored over time for organic chemical contamination. Permeation of organic chemicals into the water inside the pipe systems was found to occur in all 3 contaminated pipe systems after approximately 100 days as measured organic chemicals concentrations were significantly above those in the uncontaminated cell. Flushing experiments in which the water inside the contaminated pipes was replaced with initially clean water showed that organic chemical concentrations inside the pipe rapidly (12 days) reached their preflushing levels.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.85-91
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• 2001

The regulation of Material safety data sheets(MSDS) was required for the chemicals in use in the workplace from July 1976. Under the provisions of the workplace hazardous materials information system, employers in Korea must be provided with accurate and comprehensive MSDS. To examine the reliability of MSDS for organic solvents, 63 organic solvents and MSDS were collected from the workplace of 39 companies located in Kyonggi province. Manufacture\`s MSDS were compared with the actual composition of the collected samples, and further examined the reliability by checking whether the chemicals analyzed were included in the MSDS correctly. 38 solvents were able to analyze their composition by gas chromatography-mass selective detector(GC-MSD). Among them, 28 solvents were incorrect in their composition and contents. In some case, health hazardous or carcinogenic chemicals which were not included in the MSDS were detected from samples. As a result of evaluating whether the MSDS correspond to the regulation required by Industrial Safety and Health Act (ISHA), the information in the MSDS including hazard classification, occupational exposure level, toxicity, regulatory information were incorrectly provided, and some MSDS did not disclose carcinogenic in their MSDS, and some MSDS were not written in the standard format. From this survey, continuous monitoring and promoting correct MSDS, and analyzing the components of the solvents were required to endure the reliability of MSDS for organic solvents.

• Journal of Applied Biological Chemistry
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• v.44 no.4
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• pp.194-198
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• 2001

Contaminated sites are often abandoned for an extended period of time, thus organopollutants becoming sequestered. The information on the initial concentrations of the contaminants would be helpful for the economic bioremediation of the chemicals. The present study estimated the initial concentrations of atrazine and phenanthrene through multiple regression analyses using soil properties and the amount of chemicals available in situ. Percentage mineralized or extracted was best correlated with organic C or logarithm of organic C, and the $R^2$ values were 0.548 and 0.894 for atrazine and phenanthrene, respectively. Estimation of the initial concentration of the chemicals was then calculated from both the percentage mineralized or extracted and the amount of chemicals extracted or mineralized. Results showed that the estimation of the initial concentration of the chemical at the time of contamination is feasible.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.11a
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• pp.57-70
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• 2006

Microparticle and micropolymer retention and drainage aid systems are powerful tools for paper and board making on a variety of machines. Drawbacks attributed to the current systems sometimes include; apparent high cost, production and quality problems and in some cases a negative effect on formation. The next generation multi-component organic/inorganic systems have demonstrated their ability to decouple the effects of retention and drainage and to improve the formation and print quality for the same retention and in some cases higher retention levels. It is now possible to optimize independently retention, drainage and formation effects with the same high return on investment of current microparticle systems.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1332-1339
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• 2005

The purpose of this study is to the distributive property of organic pollutants in effluents of domestic sewage treatment plants around Youngsan River using simultaneous analysis method of 310 chemicals. The numerous organic pollutants were detected in five sampling sites, and the major chemicals were pesticides, CH type chemicals such as benzenes and polycyclic compounds, ande CHO type chemicals such as phenols and phthalates. About 14 pesticides were detected in the effluent and most of them were found in summer. 1-Chlorobenzen and p-octylphenol were frequently detected in the concentration range of $0.52{\sim}0.61\;{\mu}g/L$ and $0.04{\sim}0.89\;{\mu}g/L$, respectively. Moreover, 18 kinds of endocrine disrupters include diethylphthalate were detected in effluents. From the results of this study, therefore, we confirmed that the pesticides, CH and CHO type chemicals in domestic effluents throughout Youngsan River are required specific regulation.

• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.193-200
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• 2007

The AOPs research defined by creating a sufficient amount of OH radicals from the dissolution of organic materials through photoxidation and research for a complete elimination of residual organic materials by membrane are actively ongoing. This research focuses on the hybrid processing of AOPs and M/F membrane to dissolve and eliminate organic chemicals in drinking water which are suspected of carcinogens. For this purpose, underground water was used as a source of drinking water for the hybrid processing of AOPs oxidation and M/F membrane, and a pilot plant test device was installed indoor. Carcinogenic chemicals of VOCs and pesticide were artificially mixed with the drinking water, which was then diluted close to natural water in order to examine treatment efficiency and draw optimal operation conditions. The samples used for this experiment include four chemicals phenol, chloroform, in VOCs and parathion, carbaryl in pesticide. As a result of the experiments conducted with simple, and compound solutions, the conditions to sufficiently dissolve and eliminate carcinogenic chemicals from the hybrid processing of where carcinogens were artificially added are : (hydrogen peroxide) prescribed solution 100 mg/L under pH 5.5~6.0, and the temperature $12{\sim}16^{\circ}C$, at the normal temperature and pressure. $d-O_3$ volume of 5.0 ppm and above and 30-40 minutes of reaction time are most appropriate and using MF/UF for membrane was ideal.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.233-236
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• 2014

Organic light emitting diodes (OLEDs) received much attention from both academia and industry as the next-generation flat panel displays. However, to produce high quality OLEDs, there are still many challenges to overcome. Especially, in full color OLEDs, the intrinsic wide band gap of the blue emitting materials results in inferior efficiency compared to those of green and red emitting materials. Therefore, extensive research efforts have been devoted to develop efficient blue emitting materials. This review briefly summarizes the basics of OLEDs and introduces highlights of research efforts in blue-emitting materials.

• Polymer(Korea)
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• v.38 no.3
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• pp.299-306
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• 2014

ZnO pillared saponite was synthesized via a microwave hydrolysis method. To enhance interfacial compatibility between zinc oxide (ZnO) pillared saponite and poly lactic acid (PLA), ZnO pillared organic saponite was prepared by intercalation modification of cetyltrimethylammonium bromide. Moreover, PLA/ZnO pillared organic saponite nanocomposites were prepared by melting processing. The microstructure analysis of PLA/ZnO pillared organic saponite nanocomposites showed that ZnO pillared organic saponite was exfoliated and homogeneouslydispersed in PLA matrix. The property results showed that ZnO pillared organic saponite improved the mechanical properties and thermal stabilities of PLA/ZnO pillared organic saponite nanocomposites. Differential scanning calorimetry (DSC) demonstrated that ZnO pillared organic saponite restrained the appearance of cold crystallization, lowered the glass transition temperature and melting temperature of PLA, and improved the crystallinity of PLA. The results demonstrated that ZnO pillared organic saponite had a good interfacial compatibility and heterogeneous nucleation effect in PLA matrix, and also played an active role in accelerating the crystallization process of PLA.