• Bulletin of the Korean Chemical Society
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• 제22권2호
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• pp.183-188
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• 2001

Ionic conjugated polymer, poly(2-ethynyl-N-propargylpyridinium bromide), was prepared by the cyclopolymerization of 2-ethynyl-N-propargylpyridinium bromide on using various transition metal catalysts, or by thermal methods without adding catalyst. The polymerization of 2-ethynyl-N-propargylpyridinium bromide catalyzed by PdCl2 gave the resulting polymers in relatively high yields. The polymer structure was characterized by various instrumental methods to confirm the conjugated polymer backbone structure carrying cumulated pyridine moiety. The polymers prepared by PdCl2 in DMSO or m-cresol were completely soluble in DMF, DMSO, and formic acid. The inherent viscosities of the resulting polymers were in the range of 0.07-0.19 dL/g. Thermal properties of the polymers were also discussed.

• 한국환경보건학회지
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• 제25권3호
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• pp.83-88
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• 1999

This study was carried out to examine the behavior of THM formation in water treated with chlorine dioxide where humic acid was used as THM precursor. THM was not detected in bromide-free water, but formed in water containing bromide. When 10 mg/l of chlorine dioxide was added to water containing 5 mg/l of humic acid and bromide respectively, 20.46 ${\mu}$g/l of THM was formed. It is postulated that chlorine dioxide oxidize bromide to hydrobromous acid, which subsequently reacted with humic acids similar to chlorine reaction. The formation of THM could be reduced at low pH. Among THM formed, CHBr$_3$ was the predominant species in the alkaline solution, while CHCl$_3$ in the acidic solution. A sample pretreated with chlorine dioxide for 24h before addition of chlorine showed a reduction of 75.1% in THM formation, compared with a sample not pretreated with chlorine dioxide and a sample treated by chlorine for 24h prior to addition of chlorine dioxide also showed a reduction of 37.8% in THM formation, compared with a sample not added with chlorine dioxide. It may explain that chlorine dioxide oxidizes directly a fraction of THM.

• 대한화학회지
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• 제29권3호
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• pp.271-276
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• 1985

송아지 胸線 DNA가 單分子的 凝縮된(collapsed) 構造를 이루는 spermine 濃度에서 얻어지는 異例的 吸光度-溫度 樣相(anomalous absorbance-temperature profile)의 trough 領域에 이르는 相變移에 對한 cooperativity, enthalpy, 및 相變移 midpoint를 구하여 그 값들을 Tm 領域의 값들과 比較한 結果 그 두 그룹의 값들은 서로 相異하였으며 前者의 값들이 後者의 값들 보다 ethidium bromide에 對하여 더 銳敏하였다. Ethidium bromide 濃度를 增加시킴에 따라서 그 trough의 깊이가 작아져서 終局的으로 없어졌으나 그와 對照的으로 Tm은 實驗的으로 一定하게 維持되었다. 本 硏究結果를 基礎로 하여 DNA 凝縮 메카니즘을 推理하였다.

• 대한화학회지
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• 제20권3호
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• pp.221-228
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• 1976

$60{\%}$ dioxane 수용액에서 hydrazonyl bromide의 여러 유도체$(p-H,\;p-CH_3,\;p-OCH_3,\;p-Br,\;p-Cl\;및\;p-NO_2)$의 pH에 따르는 가수분해 반응속도를 $25^{\circ}C$에서 자외선 분광광도법으로 측정하여 넓은 pH 범위에서 잘 맞는 반응속도식을 구하였다. 가수분해 반응속도에 미치는 치한기효과를 검토하기 위하여 Hammett plot한 결과 pH 2 이하에서는 ${\Phi}$ = -0. 94, pH 4 이상에서는 ${\rho}$ = 0.54을 얻었다. pH에 따르는 반응속도 상수의 변화에 미치는 용매효과 브롬음이온효과 및 치환기효과등으로 부터 hydrazonyl bromide의 가수분해는 pH 2 이하에서는 carbonium ion 중간체를 거쳐 반응이 진행되는 $S_N1$ pH 4 이상에서는 hydrazonyl bromide에 직접 hydroxide ion이 반응하는 이른바 $S_N2$반응이 그리고 pH 2와 pH 4 사이에서는 이 두반응이 경쟁적으로 일어남을 알 수 있었다.

• 한국산업보건학회지
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• 제18권1호
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• pp.32-40
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• 2008

Methyl bromide has been used as a representative fumigant for quarantine, and several poisoning cases have occurred recently by this chemical in Korea. The purpose of this study is to evaluate workers' exposures to airborne methyl bromide in the importing and exporting plant products quarantine companies. Air samples were collected 400/200 mg Anasorb 747TM and were analyzed by gas chromatograph /flame ionization detector according to the Occupational Safety and Health Agency (OSHA) Method PV2040. Geometric mean (GM) and arithmetic mean (AM) of total 27 workers' exposure concentrations to airborne methyl bromide were 1.12 ppm and 0.24 ppm, respectively. Two exposures(12.1 ppm and 12 ppm as 8hr-TWA) of total 27 workers' exposures exceeded the Korean standard (5 ppm) of Ministry Labor, while 4 exposures (15%) exceeded the Threshold Limit Value (TLV) (1 ppm) of American Conference of Governmental Industrial Hygienists (ACGIH). Seven samples (11%) of total 63 short-term air samples exceeded the OSHA Permissible Exposure Limit (PEL) 20 ppm (Ceiling). The opening (management) task in wood fumigation by tent showed the highest short-term exposure concentrations (AM: 18.6 ppm, GM: 0.58 ppm, maximum: 340.7 ppm). The maximum level in treatment task of the same process was 2.01 ppm. Methyl bromide concentrations in opening operation was significantly higher than that in treatment operation (p<0.05). In conclusion, the GM of workers' 8hr-TWA exposures to airborne methyl chloride in the importing/exporting plant quarantine industry was estimated below the ACGIH TLV (1 ppm). However, opening task in the fumigation of wood being covered with tent or fumigation of pant products in container showed the levels exceeding ACGIH TLV (1 ppm), and opening task in the fumigation of wood being covered with tent showed the level exceeding the Korean standard of Ministry of Labor (5 ppm).

• 대한화학회지
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• 제20권6호
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• pp.479-485
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• 1976

방사성 브롬으로 표시한 브롬화 n-부틸을 사용하여 1,2,4-트리클로로벤젠용액 및 니트로 벤젠용액 내에서 브롬화칼륨과 n-브롬화부틸 사이에 일어나는 브롬교환 반응의 속도를 19,25 및 40$^{\circ}C$에서 측정하였다. 본 실험의 결과는 이 브롬 교환반응이 브롬화칼륨에 관하여 2차반응이고 n-브롬화부틸에 관하여 1차 반응임을 보여준다. $19^{\circ}C$에서의 반응속도상수 값이 1,2,4-트리클로로벤젠용액에서 $1.15{\times}10^{-4} l^2{\cdot}mole^{-2}{\cdot}sec^{-1}$이고, 니트로벤젠용액에서 $4.21{\times}10-4 l2{\cdot}mole-2{\cdot}sec-1$임을 알았다. 그리고 반응속도상수와 온도와의 관계로부터 이 교환반응에 대한 활성화 에너지, 활성화 엔탈피 및 활성화 엔트로피 값을 계산하였다.

• 한국응용곤충학회지
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• 제20권4호
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• pp.212-216
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• 1981

이 시험은 수직 사이로에 충진된 옥수수를 대상으로 M.B를 사용하여 자연중력하에서 소독할 때 M.B가스의 침투확산성 및 살충효과를 요약하면 다음과 같다. 1. 사이로 표층의 M.B가스 농도는 투약후 2시간후부터 100mg/l 이상에서 20mg/l 이하로 급격히 감소하였다. 2. 사이로 표층으로부터 3m 깊이 지점의 M.B가스 농도는 투약후 12시간이후 100mg/l 이상에서 30mg/l 이하로 감소되었으며 표층의 고농도 M.B가스가 불과 30분 이내에 3m 깊이 까지 침투되었음을 알 수 있었다. 3. 사이로 표층으로부터 고농도의 M.B가스는 13m 깊이 지점까지 1시간 이내에 침투되었으며 투약후 48시간까지 지속적으로 100mg/l 이상$\~$40mg/l 이상의 M.B가스가 검지되는 것으로 보아 자연중력하에서 옥수수를 소독하는 경우 13m 깊이 부근에 M.B 가스의 고농도 대를 형성하는 것으로 추측된다. 4. 사이로 기부(21m 지점)의 M.B가스는 $4\~20mg/l$에 불과했던 것으로 보아 M.B의 침투가 아주 적었던 것으로 판단되어진다. 5. M.B 가스의 횡 확산성은 수직 침투성에 비하여 매우 적었으며 사이로 길이 3m의 경우 투약방향으로부터 약 13m지점의 qdnl는 중심부의 약 $\frac{1}{2}$, 그리고 깊이 13m 지점에서는 지점에서는 $\frac{1}{15}\~\frac{1}{20}$의 농도에 불과하였다. 6. 투약후 24시간만에 조사한 사이로의 표층 및 기부(21m 지점)에 삽입 했던 공시충(거짓쌀도둑)은 모두 사멸되었으며 48시간후에 조사한 3m, 7m, 및 13m 지점의 공시충도 모두 사충으로 발견되었다.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.773-775
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• 2002

• Bulletin of the Korean Chemical Society
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• 제22권6호
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• pp.549-550
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• 2001

• 한국환경보건학회지
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• 제45권6호
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• pp.675-687
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• 2019

Objective: Methyl bromide (MB) fumigant has been shown to be fatal to human when was exposed. However, it were still used the significant amount in quarantine disinfection sites. The purposes of this study were to assess the MB exposure status and characteristics by fumigation-related workers and to provide supporting data for management plan. Methods: For this study, the three groups related to fumigation work were composed. A total of 107 workers were directly exposed, 20 field inspectors were indirect, and 20 general quarantines were not exposed. The urinary bromide ion concentrations in each group were analyzed by using HPLC/ICP-MS, and the working characteristics were identified using the structured questionnaire. Results: The urinary bromide ion concentration in the exposed group of fumigation workers was higher than the indirect and non-exposed groups. In the work characteristics of workers, there was a significant tendency to increase urinary bromide ion concentrations with higher fumigation work years (≤4 years: 2.84 (1.13-7.11) mg/g cr, >4-15 years: 5.36 (4.37-6.57) mg/g cr, >15-37 years: 6.69 (5.27-8.49) mg/g cr, p=0.034). In the comparison of the average number of working days per month, the more working days, the higher the urinary bromide ion concentration was statistically significant (≤12.5 days: 2.59 (1.19-5.65) mg/g cr, >12.5-19.25 days: 5.46 (4.62-6.44) mg/g cr, >19.25-27.25 days: 7.93 (5.93-10.59) mg/g cr, p=0.002). Conclusion: This study was the first nationwide survey including biological monitoring in workers exposed to methyl bromide. The results of this study were expected to be used as a reference for workers' health rights in relation to fumigation, prevention of addiction accidents, and safe management plan.