• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.135-135
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• 2001

수돗물 불소화사업이란 치아우식증 (충치)을 예방할 목적으로 0.8ppm의 불소를 수돗물에 첨가하는 공중보건사업이며, 수돗물 불소화사업이 시행되지 않고 있는 서울시내 초등학교에서는 1995년부터 불화나트륨용액 (0.2%용액으로 매주 1회 또는 0.05%용액으로 매일 1회)으로 불소양치를 실시하고 있으며, 서울시 일부 보육시설에서는 만4세-6세의 취학전 아동을 대상으로 불소용액양치사업 (0.25% 용액)을 1997년부터 실시하고 있다. (중략)

• Asian Journal of Atmospheric Environment
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• 제3권1호
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• pp.27-41
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• 2009

Internally mixed states of submicron particles during transport from the Asian continent to the Pacific Ocean were analyzed using a single-particle time-offlight mass spectrometer. The observation was conducted at Tsukuba in Japan in the spring of 2005 in order to investigate springtime transport of particles from the continent. The sum of ion intensities of sulfate (${HSO_4}^-$) detected in particles originating from the continental air masses counted for 75% of that in all particles during the observation. By analyzing correlations among compounds, origins and internally mixed states of compounds were estimated. It was found that nitrate was mixed with sulfate-rich particles as the air mass approached Japan. It was confirmed that Asian mineral dust particles played significant roles for transport of continental sulfate to Japan. As a result of analysis on internal mixing of chlorine and nitrate, it was implied that the chlorine loss in fine sea salt particles had already proceeded at Tsukuba. It was characteristic that fluoride ions were significantly detected, coal combustion in the Asian Continent can be an important source of fluorides detected in Japan through the westward transportation of fine particles including fluorides.

• Safety and Health at Work
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• 제2권1호
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• pp.39-51
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• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.

• 대한화학회지
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• 제40권3호
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• pp.187-195
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• 1996

한 분자의 시안화수소와 두 분자의 플루오르화수소 사이에 생성 가능한 다섯개의 수소결합 삼합체들에 대하여 TZ+P 수준의 기본조를 사용하여 ab initio 계산을 하였다. 이것들의 몇 가지 바닥상태 성질을 구하여 단위체와 이합체들의 대응하는 성질과 비교하였다. 앞으로 얻울 수 있게 될 실험 자료들을 보충하기 위하여 계산한 평형 기하구조, 안정화 에너지 및 쌍극자 모멘트를 나타냈다. 이 수준의 근사법에서는 분자내 결합거리는 항상 실험값보다 작게 계산되었지만, 분자간 거리와 쌍극자 모멘트는 크게 계산되었다. 다섯개의 삼합체중에서 HCN$(HF)_2$가 가장 안정하고, 또한, $(HCN)_2HF$보다도 더 안정한 것으로 나타났다. 분자간 상호작용의 비가감성에 대한 전형적인 특징은 HCN$(HF)_2$에서 비교적 강했다.

• 대한방사성의약품학회지
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• 제3권2호
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• pp.116-121
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• 2017

To overcome the low reactivity and solubility of alkali metal fluorides (MFs), various types of phase transfer catalysts (PTCs) have been developed over the last decades. However, since the fluoride activated by such PTC sometimes has a strong basicity, it may cause various side reactions such as elimination reaction or hydroxylation reaction in the nucleophilic fluorination reaction. Also, they may cause separation problems in the compound purification process. In recent advanced study, various PTCs have been developed to solve these problem of conventional catalyst. In this review, we would like to introduce three kinds of novel multifunctional organic catalysts such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), easy separable pyrene-tagged ionic liquid (PIL) by reduced graphene oxide (rGO), and tri-tert-butanolamine organic catalyst.

• 대한약리학회지
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• 제8권2호
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• pp.41-47
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• 1972

Fluorides were supposed to exert a stimulatory action on the catecholamine release. In this study, the authors attempted to investigate the action of sodium fluoride on the catecholamine release from the isolated perfused cow adrenal gland and rat heart. And also the inhibitory effect of sodium fluoride on the monoamine oxidase activity in rat heart and liver mitochondria was investigated. The monoamine oxidase activity was measured by the conversion of benzylamine to benzaldehyde. The results obtained were follows; 1. Sodium fluoride stimulated the release of catecholamine from the isolated perfused cow adrenal gland and rat heart. 2. Sodium fluoride inhibited the rat heart and liver mitochondrial monoamine oxidase activity.

• 한국광학회지
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• 제3권2호
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• pp.92-100
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• 1992

회전검광자형의 분광타원해석기를 제작하였다. 각 부품의 미소결함에 의한 오차를 고려하여 이들이 타원해석상수들에 미치는 영향을 최소로 하는 배치를 결정하였다. Straight through operation의 성능평가 결과 300nm~850nm의 파장대역에 걸쳐 tan$\psi$와 cos$\Delta$의 편차는 0.2%내외로 만족할 만한 것으로 판단되었다. SE를 사용하여 불화박막의 굴절율및 void분포상태를 측정하였고 응용성에 관하여 논의하였다.

• 대한화학회지
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• 제6권1호
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• pp.73-77
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• 1962

Yields of hydrogen, methane, carbon monoxide, formaldehyde and ethylene glycol by gamma-radiolysis of methanol have been determined at room temperature and compared with values reported in the literature. The G-values obtained by the present studies are as follows: $G(H_2)=4.98,\;G(CH_4)=0.28,\;G(CO)=0.09,\;G(HCHO)=2.14\;and\;G(C_2H_6O_2)=3.07.$ The effects of water, methyl borate and alkali halides added to methanol prior to radiolysis have also been investigated. It is observed that alkali iodides and bromides affect the G-values, particularly, of hydrogen, formaldehyde and/or ethylene glycol, whereas alkali chlorides and fluorides have less pronounced effects.

• The Journal of Korean Physical Therapy
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• 제2권1호
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• pp.113-122
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• 1990

Osteoporosis is a major underlying cause of bone fracture in postmenopausal women and older person in general, and so it is a major public health problem. It is a condition in which bone mass decreases, causing bones to be more susceptible to fracture. A trivial trauma can easily cause one or more bones to break in a person with severe osteoporosis. Physicians and patients alike are concerned with the optimum approach to the treatment and prevention of osteoporosis. The diagnostic method and proper use of agents, such as calcium, vitamin D, estrogen, and fluorides, as well as the role of exercise are issues that have generated major research efforts. So these are to be mentioned in this paper.

• 대한방사성의약품학회지
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• 제7권2호
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• pp.141-146
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• 2021

With increasing interest in fluorinated compounds, nucleophilic fluorination reaction has been generally used for synthesizing fluorine-containing chemicals. However, alkali metal fluorides (MFs) generally have low solubility and reactivity in organic solvent. To overcome these problems, various phase transfer catalysts (PTCs) have been investigated. Calix-arene is known as to capture the metal cation(M⁺), and therefore in this review, we would like to introduce several kinds of calix-arene based PTCs, such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), oligo-ethylene glycol linked bis-triethyleneglycol crown-5-calix[4]arene (BTC5A), and ionic liquid functionalized calix-arene based catalyst, as well as ion-pair receptor crown-6-calix[4]arene-capped calix[4]pyrrole.