• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.213-216
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• 2004

This work was based on the hypotheses that fingernail clippings can be used as a biomarker for the subchronic exposure to fluoride. This study was conducted to prove the hypotheses and fingernail clippings were collected form 120 preschool children aged $3{\sim}6$ residing in Jumunjin(community water fluoridation area) and Kangnung(non-fluoridation area). The acid-diffusible fluoride in the fingernail clipping was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean fingernail fluoride as the children's living area were 4.49ug/g(SD 2.43) to Jumunjin and 2.68ug/g(SD 1.13) to Kangnung. As would be expected, the fluoride concentration in fingernail clippings were significantly different between the two geographical groups(p<0.001) determined by t-test.

• The Journal of the Korean dental association
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• v.56 no.8
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• pp.424-431
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• 2018

Silver diamine fluoride (SDF) is an alkaline topical solution and it derives from the conjunction of silver nitrate and fluoride. It reduces the growth of cariogenic bacteria, inhibits degradation of dentinal collagen, impedes demineralization and enhances remineralization. It is inexpensive due to the low cost of materials and its application to dental surface is very simple and requires relatively short chair time. Previous studies have shown that the dental caries prevention effect of SDF is superior or similar to topical fluoride application. The main disadvantage of SDF is its esthetic result, and it permanently blacken carious enamel and dentin. The use of SDF has not yet been approved in Korea, but it may be helpful to prevent and treat dental caries in patients with special health care needs and uncooperative young patients.

• The Korean Journal of Pharmacology
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• v.8 no.2
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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.

• Analytical Science and Technology
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• v.8 no.4
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• pp.877-880
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• 1995

The determination of fluoride and the nutritious calcium in infusion of teas are explained. Tea leaves were pulverized and were immersed in boiling water. The solution was filtered and fluoride, calcium and oxalic acid were determined by the ion chromatography. The quantities of fluoride, calcium and oxalate ions extracted from 100 g of tea leaves were calculated. Tea leaves were also immersed in 0.5 M hydrochloric acid and extracted oxalate and calcium ions were analyzed. The free oxalic acid and calcium were extracted in boiling water and the total ones were extracted in hydrochloric acid. The quantity of calcium oxalate was calculated from the total and the free oxalic acids. The free calcium was estimated to be nutritious.

• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.510-518
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• 2003

The fluoride work management of water supply conveyance has been recommending by the WHO to prevent of tooth decay. Fluoridation of public water supplies has been practiced since 1945. The present approximately 67 countries reported community water fluoridation benefiting many cities. At our country, Fluoridation began in 1981 in Chongiu and Jinhea. In 2002, approximately 40 cities have large populations consuming fluoridated water. But Chongiu stopped fluoridation water works. Few public health measures have been accorded greater clinical and laboratory research, epidemiological study, clinical trials, and public attention than has water fluoridation. In this study, chemical analysis of Sodium Silicofluoride and Fluoride Feed Equipment analyzed. And this study proposed to Fluoride concentration experimental (lab. and field exp.), economics analysis, prevention effect. This study can be decided on the concentration of fluoride injection in Water Fluoridation. Hereafter, this study will be useful in safety and economics of Water Fluoridation in the future.

• Journal of Environmental Health Sciences
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• v.19 no.1
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• pp.51-56
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• 1993

This study was performed to find the ability of bituminous coal fly ash to remove fluoride from water and wastewater at different fluoride concentration, reaction temperature, reaction time and pH. The removal of fluoride is favorable at low concentration, high temperature and acidic pH. With the increase in the initial fluoride concentration, the amount adsorbed increased. Adsorption process was exothermic at pH 2.0. Physisorption process was predominant over pH 2.3, while Chemisorption was under pH 2.3. Fluoride uptake by fly ash was conducted the adherence of fluoride on the active surface sites of adsorbent and its intraparticle diffusion within adsorbent. The values of rate constants of adsorption were 3.028X 10$^{-3}$, 4.715X 10$^{-3}$, 2.88X 10$^{-3}$ (min) and intraparticle diffusion were 1.434X10$^{-3}$, 3.012X10$^{-3}$, 5.635X10$^{-3}$ at each temperatures.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1287-1289
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• 2009

Three different fluoride compounds were used for preparation of $BaAl_2S_4$:Eu thin-films. The emission intensity of these devices were higher than that of the thin-films deposited without fluoride materials, and the appropriate annealing temperature decreased with fluoride dopants. It is related to the fluoride compounds accelerate the crystallization of $BaAl_2S_4$ at low temperature.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.77-88
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• 2013

The computational study on the fluoride ion binding with bis(bora)calix[4]arene has been performed using density functional theory and ONIOM model. The computed structure and fluorescent behavior of bis(bora)calix[4]arene was corresponded to experiment value. The binding energy for fluoride anion is computed to be 28.05kJ/mol in the chloroform solution. We also predicted that this sensing mechanism is only valid for fluoride ion in halogens. By analyzing molecular orbitals, binding with fluoride ion reduces energy differences between HOMO and LUMO, which leads to fluorescent sensing.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.556-570
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• 2021

This study presents the data analysis results of groundwater chemistry and the occurrence of fluoride in groundwater obtained from the groundwater quality monitoring network of Korea. The groundwater data were collected from the National Groundwater Information Center and censored for erratic values and charge balance (±10%). From the geochemical graphs and various ionic ratios, it was observed that the Ca-HCO₃ type was predominant in Korean groundwater. In addition, water-rock interaction was identified as a key chemical process controlling groundwater chemistry, while precipitation and evaporation were found to be less important. According to a non-parametric trend test, at p=0.05, the concentration of fluoride in groundwater did not increase significantly and only 4.3% of the total groundwater exceeded the Korean drinking water standard of 1.5 mg/L. However, student t-tests revealed that the fluoride concentrations were closely associated with the lithologies of tuff, granite porphyry, and metamorphic rocks showing distinctively high levels. This study enhances our understanding of groundwater chemical composition and major controlling factors of fluoride occurrence and distribution in Korean groundwater.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.555-566
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• 2008

Hydrogeochemical study in Samseung area (Boeun, Chungbuk) and waterrock interaction experiment using rock samples from the area were performed to elucidate the fluoride source in groundwater and explaining geochemical behavior of fluoride ion. Fluoride concentration of public water supply mostly using groundwater in Boeun area was significantly higher in South Korea. The maximum fluoride concentration of the study area was 3.9 mg/L, and 23% of samples exceeded the Korean Drinking Water Standard of fluoride (1.5 mg/L). The average concentration of fluoride was 1.0 mg/L and median was 0.5 mg/L. Because of high skewness (1.3), median value is more appropriate to represent fluoride level of this area. The relationships between fluoride ion and geochemical parameters ($Na^+$, $HCO_3$, pH, etc.) indicated that the degree of waterrock interaction was not significant. However, high fluoride samples were observed in $NaHCO_3$ type on Piper's diagram. The negative relationship between fluoride and $NO_3$ ion which might originate from surface contaminants was obvious. These results indicate that fluoride ion in groundwater is geogenic origin. The source of fluoride was proved by waterrock interaction batch test. Fluoride concentration increased up to 1.2 mg/L after 96 hours of reaction between water and biotite granite. However, the relationship between well depth and fluoride ion, and groundwater age and fluoride ion was not clear. This indicates that fluoride ion is not correlated with degree of waterrock interaction in this area but local heterogeneity of fluoriderich minerals in granite terrain. High fluoride concentration in Boeun area seems to be correlated with distribution of permeable structures in hard rocks such as lineaments and faults of this area. This entails that the deep bedrock groundwater discharges through the permeable structures and mixed with shallow groundwater.