• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.913-916
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• 1999

Fluorine modified diisocyanate(FMD) was synthesized from tris(6-isocyanatohexyl)isocyanurate(TIHI) and N-ethyl-N-2-hydroxyethyl-perfluorooctanesulfonamide(HFA). Fluorine modified polyurethane(FMPU) was also synthesized from FMD and poly(tetramethylene) glycol(PTMG). Modified polyurethanes were made by blending FMPU into the polyester type base polyurethane(BPU). Surface and thermal properties of the blended BPU film was measured by contact angle measurement and DSC. As the amounts of FMPU was increased from 0 wt % to 1 wt %, the surface energy was dramatically decreased from 47.82 dyne/cm to 17.64 dyne/cm. But we observed little change of the contact angle with further increase in the amount of the FMPU up to 10 wt %. The data meant that the surface of the blended polyurethanes was hydrophobic due to the surface arrangement of the fluorine containing moiety in FMPU. Phase separation was induced by the incompatibility of FMPU and BPU for the samples having over 5 wt % of FMPU. The thermal analysis data of these samples showed the thermal behavior of the FMPU itself.

• Journal of Oriental Neuropsychiatry
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• v.14 no.2
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• pp.213-218
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• 2003

This is a case report of a patient with Tourett's disorder treated by Ukgan-san. We evaluated the patient Tourett's disorder by behavior and sound. His tic behaviors like eye blinking, shoulder shrugging, head jerking, facial frimace have been shown frequently, and His phonic tic symptoms like coughing, throat clearing, sniffing have been presented frequently, too. We diagnosed his condition as Wind-syndrome Caused by Hyperactivity of Liver-yang by patient's redish face, taut pulse, Left umbilical throb. So we treated the patient with Ukgan-san. and the score of Yale Global Tic Severity Scale(YGTSS) was 30 at the start of treatment. and the score of YGTSS was 3 at the end. We found that Ukgan-san was effective for the patient with Tourett's disorder.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1209-1212
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• 2010

본 연구는 제주지역 일부 초, 중학생들의 간접흡연 실태와 그로 인한 현재 흡연 여부 관계를 분석하여 초, 중학생들의 흡연 예방 교육 계획 및 수립에 기초 자료를 제공하고자 본 연구를 시도하였다. 자료 수집 기간은 2009년 6월 29일부터 7월 11일까지 제주특별자치도내 초등학교 5, 6학년 아동 464명과 중학생 475명을 대상으로 설문지를 이용하여 조사하였다. 연구 대상자들의 간접흡연 노출 관련성은 가정불화, 성적, 친구관계스트레스가 있는 대상자에게서 높게 조사되었고, 가족 및 주변인의 흡연유무에 따른 간접흡연 실태는 부모 및 친구의 흡연으로 간접흡연에 노출되었으며 통계적으로 유의한 차이를 보였다. 간접흡연의 주제공자는 아버지며, 주 간접흡연 피해 장소는 집으로 나타났다. 간접흡연 노출 유무를 종속변수로 한 로지스틱 회귀분석 결과는 흡연하는 아버지를 둔 대상자가 그렇지 않은 대상자에 비해 간접흡연 노출이 높았으며, 흡연하는 친구를 둔 대상자는 그렇지 않은 대상자에 비해 간접흡연 노출이 높게 나타났다. 현재흡연 여부를 종속변수로 한 로지스틱 회귀분석의 결과는 남학생이 여학생에 비해, 중학생이 초등학생에 비해 현재흡연율이 높았고, 엄한 가정 분위기 속에서 생활하고 있는 대상자와 흡연하는 친구를 둔 대상자는 그렇지 않은 대상자에 비해 현재흡연율이 높았으며, 간접흡연에 노출 되었던 대상자에게서 현재흡연율이 높게 나타났다. 이상의 결과를 종합하여 볼 때 초, 중학생의 간접흡연 실태는 심각한 사회문제이다. 또한 대상자들의 현재 흡연은 간접흡연 노출과 관련이 있는 것으로 볼 수 있었다. 이러한 간접흡연의 노출 및 그로 인한 흡연율을 줄이기 위해서는 가정 및 학교와 공공장소 등에서 간접흡연에 노출되지 않는 제도적 및 환경적인 조치들이 우선되어야 할 것이며, 학생들을 대상으로 간접흡연에 대한 간접흡연 예방 교육 및 대처방안 교육이 조기에 지속적으로 실시되어야 하겠다. 또한 유치원에서부터 고등학교에 이르기까지 모든 학생들에게 필수적으로 흡연예방 교육을 수강하게 하고, 교사들을 위한 연수교육 실시, 학교 흡연예방사업에 부모나 가족을 참여, 흡연예방 사업의 정기적인 평가 실시 등 국가적인 정책이 동반되어야 할 것이다.

• Analytical Science and Technology
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• v.30 no.5
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• pp.240-251
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• 2017

1,1,1,2-Tetrafluoroethane (HFC-134a), which is used as refrigerant in air conditioners, has been recently regulated as a greenhouse gas and is recommended for reuse by refining. It is very important to quantitatively analyze trace impurities present in the refrigerant to evaluate the criteria for reuse. In this study, trace impurities including C, H, Cl, and F, which are difficult to quantify because there are no reference materials, were quantitatively analyzed by a gas chromatograph-atomic emission detector (GC/AED); for this analysis, this was preceded by a qualitative analysis with a GC-mass selective detector (GC/MSD). In addition, the AED response was investigated using a hydrocarbon mixed reference material, which was proportional to the number of atoms in the component. Fifteen refrigerant components were detected as trace impurities in HFC-134a by qualitative analysis of trace impurities including C, H, Cl, and F in the samples. Based on the results of the qualitative analysis, quantitative analysis of trace impurities using AED showed that the highest mole fractions were for the $CHClF_2$ component ($45438.38{\mu}mol/mol$) in one sample and for the $C_2H_2ClF_3$ component ($1311.47{\mu}mol/mol$) in another sample. From this study, it has been shown that it is possible for this analytical method to be applied to the qualitative and quantitative analysis of trace compounds in refrigerants, which are difficult to quantify because of the absence of reference materials.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.28-35
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• 2020

This study aimed to investigate the differences in the upper and lower limits of the 95% distribution of fasting blood glucose (FBG) by age groups. We also analyzed the changes in the mean values and dispersion of the data using the Korean Blood Glucose Reference Standard raw data published by the National Health Insurance Service (NHIS). Furthermore, the trends among 16 administrative districts were analyzed and any gender differences were determined. We also assessed whether the study results correlated with the relative standard uncertainty, as published by the NHIS. On the dispersion analysis using the differences between the upper and lower limits of the 95% distribution of FBG by age group, there were significant differences across gender and administrative districts (P<0.05). The gender differences in FBG measurements, as published by the NHIS, were significant across different administrative districts and age groups (P<0.001). This confirmed the need to recalculate the blood glucose reference standards for men and women. No significant correlation was observed between the relative standard uncertainty, as published by NHIS, and the dispersion and number of measurements analyzed in this study. However, it showed a high correlation with the measured mean value (R²=0.95). Therefore, further research on the reference standard and uncertainty is needed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.187-194
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• 2005

This paper deals with a waterproof and mechanical feature of concrete using an inorganic self waterproof agent. The waterproof agents having been used in our country were a membrane agent, penetration agent and an organic waterproof agent. However, these agents have a lot of problems such as losing the effect of waterproof in the environment of lots of water, the difficulty of dispersion. For the clear of problems of these water -proof agents, we used the inorganic waterproof agent. This agent was made from inorganic fluosilicate. Generally, a waterproof agent has been used only for the waterproof effect. In this paper, however through the some tests of concrete using the inorganic self waterproof agent, we recognized that the concrete using the agent is more excellent in some peculiar properties than general concrete's properties. In this paper, we performed compressive strength, permeability, pore volume test, etc. As a result, the concrete of using the agent is more excellent in economy, waterproof, compressive strength.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.48-53
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• 2017

Since the number and the amount of toxic substances handled by domestic companies have been increased, the possibility of serious chemical accidents has become severe. According to Chemistry Safety Clearing-house (CSC), the number of chemical accidents for the last five years has been rapidly raised. A representative example which shows the serious impact of a chemical accident is HF (Hydrogen Fluoride) accident generated in Gumi in 2012. In order to make effective responses for mitigating losses of accidents, the most suitable consequence model has to be selected and implemented throughout the considerations of chemical properties and environments. Even if each consequence model has been verified by the results of experiments, it is necessary to analyze and compare the usability of them according to various scenarios. In this study, the Gumi HF accident is simulated by HGSYSTEM, which is the most specialized model for the release and dispersion of HF. It is found that the ending point of ERPG-2 is about 1 km from the accident point. In order to investigate the usability of the most representative consequence models (ALOHA and CARIS), the results of them are compared with one of HGSYSTEM.

• Journal of The Korean Society of Clinical Toxicology
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• v.11 no.2
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• pp.106-113
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• 2013

Purpose: The purpose of this study is to verify the influence of a massive hydrofluoric acid spill on community health through patients who claimed to have been exposed. Methods: We analyzed 2459 patients who visited our emergency department with the claim of exposure to hydrofluoric acid, and retrospective analyses were performed. We analyzed changes in numbers of visitors per day from the day of the accidental hydrofluoric acid spill, symptoms presented by the 1924 patients, and general characteristics. Comparisons of symptoms and hematologic characteristics were made between the initially set evacuation zone(1.3 km radius parameters from the spill) and the outer zone. Results: A total of 2,459 patients who claimed exposure visited our ED from 27 September 2012 to 23 October 2012, and there was a significant increase in the number of visiting patients from day 8 of the hydrofluoric acid spill. The most common complaints were a sore throat, 729(37.9%) and no specific symptom with health concern, 547 (28.4%). Statistically significant findings were pulmonary symptoms (p=0.001), nasal symptoms (p=0.001), diarrhea (p=0.023), and skin symptoms (p=0.007). In hematologic study, a statistically significant difference was observed in white blood cell count (p=0.018), creatine phosphokinase (p<0.001), erythrocyte sediment rate (p=0.013), and phosphorus (p<0.001). Conclusion: A significant increase in the number of patients was observed one week after the accidental spill of hydrofluoric acid. The most frequent symptoms were sore throat, headache, cough, and sputum. Statistically significant increase in creatine phosphokinase level and decrease in phosphorus level were noted in patients within the evacuation zone.

• Clean Technology
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• v.18 no.3
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• pp.301-306
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• 2012

Rapidly growing mobile machines such as tablet PC and smart phone are equipped with touch screen panel using a sturdy material for products surface protection. Therefore, surge of chemically strengthened glass was increased and the amount of waste matter is proportional to demand. The purpose of this study is environmental impact assessment on touch screen panel of chemically strengthened glass by material life cycle assessment (MLCA). We used CES of Granta, SimaPro and Gabi software for MLCA. Chemically strengthened glass (2.7, 5.7 and 10.3 inch) was calculated to environmental impact assessment by Granta software under two cases. One case is Landfill and the other case is Reuse. As a result, in case of reuse, energy values of 2.7, 5.7 and 10.3 inches were reduced by an average of 51.4%, $CO_2$ values were reduced by an average of 46.6% than Landfill case, respectively. We assessed impact categories of 11 types using SimaPro software. As a result, the contents of fossil fuels, inorganics and climate change have a huge impact than the other impact categories. And the main cause of environmental impact is antimony and hydrogen fluoride in Gabi results.

• Journal of the Korean Chemical Society
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• v.27 no.4
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• pp.279-286
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• 1983

An apparatus was made for the electrodeposition of alpha emitting actinide nuclides, $^{207}Bi$ and $^{210}Po$. The electrodeposition was made on a polished stainless steel plate cathode. The anode was made of platinum wire and to stir the solution. With the ammonium chloride as electrolyte initial pH = 4, chloride concentration = 0.6M and solution volume = 15ml, a current of 1.5 ampere(current density = 0.59A/$cm^2$) was flowed for 100 minutes for the quantitative recovery of electrodeposition and on average recovery of 98.3% was obtained within ${\pm}$0.7% uncertainty. Alpha spectrometry of the electrodeposited sample showed alpha peaks from $^{210}Po, ^{234}U$ and $^{239}Pu$ having energy resolution (FWHM) of 18.3, 21.8 and 36.0 keV respectively. The electrodeposition and alpha spectrometry for a natural uranium sample of domestic origin gave $^{238}U : ^{234}U = 1 : 6.1{\times}10^{-5}$ and for a neutron-irradiated uranium sample did $^{238}U : ^{239}Pu : ^{241}Am = 100 : 0.0263 : 5.20{times}10^{-5}$. The result of $^{238}U$ determination in the irradiated sample by electrodeposition-alpha spectrometry was in accord within ${\pm}1.6%$ of relative error with the results of solid fluorimetry and mass spectrometry. For $^{239}Pu$ the result of electrodeposition-alpha spectrometry was in accord within ${\pm}$4.0% of relative error with the results of anion exchange separation and the thenoyltrifluoroacetone(TTA) extraction both followed by alpha spectrometries.