• Fire Science and Engineering
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• v.32 no.2
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• pp.118-129
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• 2018

This study analyzed the recent serious disaster cases of chemical extinguishing agent poisoning and suffocation investigated by KOSHA and proposed the safe use of chemical substances, including the chemical extinguishing agent. An analysis of the statistical figures an increase in the number and variations of chemical poisoning and suffocation cases in industry between 2011~2016 increased. Unlike other physical accidents, chemical accidents are very high in severity and it is difficult to identify the chemical hazard and risk. To prevent chemical disasters, it is essential to develop and use an easy chemical risk assessment tool. For the safe use of chemical substances, in which it is difficult to carry out hazard identification and risk assessments, this thesis presents the useful chemical recognition and risk assessment tools, CHEM-i and CHARM developed by KOSHA.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.454-461
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• 2021

Background: Fish and fishery products (FFPs) unintentionally contaminated with various environmental pollutants are major exposure pathways for humans. To protect human health from the consumption of contaminated FFPs, it is essential to develop a systematic tool for evaluating exposure and risks. Objectives: To regularly, accurately, and quickly evaluate adverse health outcomes due to FFPs contamination, we developed an automated dietary exposure and risk assessment system called HERA (the Human Exposure and Risk Assessment system for chemicals in FFPs). The aim of this study was to develop an overall architecture design and demonstrate the major features of the HERA system. Methods: For the HERA system, the architecture framework consisted of multi-layer stacks from infrastructure to fish exposure and risk assessment layers. To compile different contamination levels and types of seafood consumption datasets, the data models were designed for the classification codes of FFP items, contaminants, and health-based guidance values (HBGVs). A systematic data pipeline for summarizing exposure factors was constructed through down-scaling and preprocessing the 24-hour dietary recalls raw dataset from the Korea National Health and Nutrition Examination Survey (KNAHES). Results: According to the designed data models for the classification codes, we standardized 167 seafood items and 2,741 contaminants. Subsequently, we implemented two major functional workflows: 1) preparation and 2) main process. The HERA system was developed to enable risk assessors to accumulate the concentration databases sustainably and estimate exposure levels for several populations linked to seafood consumption data in KNAHES in a user-friendly manner and in a local PC environment. Conclusions: The HERA system will support policy-makers in making risk management decisions based on a nation-wide risk assessment for FFPs.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.616-623
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• 1994

Conductive Polypyrrole films have been synthesized by electrochemical method in nucleophilic solvent such as N, N-dimetylformamide(DMF), dimethylsulfoxide(DMSO). The effect of protic acid as supporting electrolyte to decrease the nucleophilicity of the solvent was studied. Cyclic voltammetry, I-t transients were carried out to investigate the electrodeposition of conductive polypyrrole film on platinum electrode. Three peaks of 0.65V, 0.85V, and 1.2V vs. $Ag/AgNO_3$ indicated oxidation of monomer, oxidation of pyrrole to the platinum electrode and decomposition of polypyrrole film, respectively. With the I-t transients, nucleation process was confirmed and from obtained linear fits of I vs.t2resembles the metal film formation, and 2.15-2.26 of n-value could be calculated. As concentration of pyrrole or prolic acid was increased, the conductivity of polypyrrole film increased linearly. Tensile strength and elongation were investigated for comparing the mechanical properties and also SEM was performed for morphology investigation.

• Journal of Forest and Environmental Science
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• v.34 no.5
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• pp.376-381
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• 2018

For the control of oak wilt caused by Raffaelea quercus-mongolicae, an antifungal microorganism, Streptomyces blastmyceticus, was used as a potential agent. Culture suspension of S. blastmyceticus was injected into Quercus mongolicae in the research forest of Kangwon National University by $ChemJet^{(R)}$ trunk injection and Macro-infusion at root flare injection. $Alamo^{(R)}$ (a.i., propiconazole 14.5%), a fungicide currently used for the control of oak wilt in USA, was also treated by both methods to compare the efficacy. For preventive efficacy, culture suspension of the pathogen was inoculated at 1 month after injection of either agent. Tested trees were cut at 3 months after treatment, stained with 1% Fuchsin acid, and then non-conductive area (NCA) and re-isolation frequency (RIF) of oak wilt fungus were compared among treatments. While NCA was the highest as 47.3% in pathogen only treatment, it was the lowest as 16.0% in sterilized water treatment by Macro-infusion. NCAs of Alamo treatment by Macro-infusion and ChemJet injection were 25.3% and 32.1%, respectively. NCA of S.blastmyceticus treatment by ChemJet injection was 32.3%, similar with Alamo treatment's by ChemJet injection. All treatments by either injection method showed significantly lower NCA compared to the pathogen only treatment. These results indicate that S. blastmyceticus injection shows the preventive efficacy against oak wilt disease by suppressing the growth of pathogen injected. NCA of Macro-infusion injection of sterilized water was lower as 16.0%, compared to 21.3% of ChemJet injection. It means that Macro-infusion is more effective in translocation of sterilized water than ChemJet injection by even distribution. RIF from wood discs of treated trees showed high in pathogen only treatment, but relatively low in S. blastmyceticus treatment. RIF results were correlated with NCA results. From the above results, it was confirmed that S. blastmyceticus showed preventive efficacy against oak wilt disease by ChemJet trunk or Macro-infusion at root flare injection.

• Journal of the Korean Applied Science and Technology
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• v.19 no.3
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• pp.167-173
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• 2002

The isoflavone as a derivatives of flavone is colorless crystalline compounds. It acts on synthesis of fibronectine, collagen III, collagen I in human normal fibroblast by same biological activity to animal hormone. In this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using microemulsion containing isoflavone. The results of microemulsion stability test by centrifugation, storage in incubator and circulation chamber showed that separation of phase did not appear after 30 days. By the skin flexibility test, it has confirmed efficiency and effect as cosmetics materials. As the result, the microemulsion showed that skin flexibility factor improved up to 7.6%. We could confirm that O/W type microemulsion was stable system.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.420-421
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• 2006

The cost-effective reduction of greenhouse gas(GHG) emission to avert the most severe impacts of climate change remains one of the widely accepted priorities for global action. In order to facilitate cost-effective abatement strategies, the Kyoto Protocol introduced three mechanisms, or flexible instruments, the Emissions Trading(ET), the Joint Implementation(JI) and the Clean Development Mechanism(CDM). The CDM enables Annex I countries to the Kyoto Protocol to partially meet cost-effectively their emission reduction commitments by undertaking GHG mitigation Projects in developing countries, which do not have any GHG abatement obligations and where the emission reductions are cheaper. One of the major barriers hampering the wide spread implementation of CDM is the high transaction costs associated with the initial identification of promising CDM projects. This paper presents development of a pre-validation program of CDM. The developed program may provide a useful aid to potential investors and project developers as a supportive pre-evaluation tool, and may become an effective tool for the promotion of renewable energy and fuel switching projects.

• Applied Biological Chemistry
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• v.12
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• pp.13-17
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• 1969

The fractions of protein, albumin, globulin, oryzenin, and prolamine extracted from 20 varieties of rice were determined, which include upland and paddy rice with both waxy and nonwaxy types. The protein content is higher in the waxy type and especially in upland rice. The content of oryzenin and albumin were likewise higher in the waxy and upland types. The results were discussed in the view point of nutrition.

• Bulletin of the Korean Chemical Society
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• v.25 no.3
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• pp.357-360
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• 2004

We developed in the present study molecular imprinted polymers (MIPs), using single templates (pentoxifylline, caffeine and theophylline) and mixed-templates (pentoxifylline-caffeine, pentoxifylline-theophylline and caffeine-theophylline). The MIPs were prepared with methacrylic acid (MAA) as the monomer, ethylene glycol dimetharylate (EGDMA) as the crosslinker and 2,2'-azobis(isobutyronitrile) (AIBN) as the initiator. The obtained polymer particles (particle size after grinding was about 25-35 ${\mu}$m) were packed into a HPLC column (3.9 mm i.d. ${\times}$ 150 mm). The selectivity and chromatographic characteristics of the MIPs were studied using acetonitrile as the mobile phase at a flow rate of 0.8 mL/min. UV detector wavelength was set at 270 nm. Different single template MIPs showed different molecular recognitions to the templates and the structurally analogues, according to the rigidity and steric hindrance of the compounds. Recognition was improved on the mixed-template MIPs as a result of the cooperation or sum effect of the templates, whereas on the pentoxifylline-theophylline imprinted polymer, the highest selectivity and affinity were obtained. Separations of the test compounds on different polymers were also investigated.

• Journal of the Korean Applied Science and Technology
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• v.15 no.1
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• pp.79-90
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• 1998

One of the objectives of this study were to develop a process for manufacturing activated carbons from agricultural by-products(rice shells and saw dust) and another is to measure the iodine number, ash content and removal ratio of COD. The other is to compare those values with those of commercialized activated carbons. Agricultural by-products based activated carbons were manufactured through the steam-reaction method. A rotary kiln type furnace was used for both carbonization and activation. The optimum operating temperatures for carbonization and activation were $650^{\circ}C$ and $900^{\circ}C$, respectively. For the activated carbons produced under these conditions, the iodine number was 1,127mg/g. Especially, removal efficiency of COD was 61.5% for 40mg/L of wastewater and 30% for 150mg/L of SLS(Sodium Lauryl Sulfate).

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1156-1163
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• 1996

This study is related to the investigation of the characteristics of quaternary ammonium salt catalyst on the addition reaction of carbon dioxide and glycidyl methacrylate(GMA) to form(2-oxo-1,3-dioxolane-4-yl)methacrylate(DOMA). Among the salts tested, the ones with higher alkyl chain length and with more nucleophilic counter anion showed a higher catalytic activity. Mixed catalysts of NaI and 18-crown-6 showed a good yield of DOMA, but when they are used alone, they showed no catalytic activity. The DOMA monomer was obtained in low polar solvents, while poly(DOMA) could be directly synthesized in aprotic dipolar solvents. Kinetic studies carried out by measuring $CO_2$ pressure in a high pressure batch reactor showed that the reaction rate was first order to the concentration of GMA and $CO_2$ respectively. The rate constant(k) was 0.56L/mol hr and Henry's constant(H') of $CO_2$ in diglyme at $80^{\circ}C$ was $6.5{\times}10^{-4}mol/L{\cdot}kPa$.