• Title/Summary/Keyword: 태

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Characterization of Heavy Metals in the Stream Sediment around an Old Zinc Mine (가학광산 지역 하천 저니토 중금속의 화학적 특성)

  • Yoo, Sun-Ho;Ro, Kwang-Jun;Lee, Sang-Mo;Park, Moo-Eon;Kim, Kye-Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.29 no.4
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    • pp.432-438
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    • 1996
  • This study was carried out to prepare information for the establishment of countermeasures for an area contaminated with minewaste from an old zinc mine at Kahak-long in Kwangmyong. Minewaste and bottom sediments from the streams in this area were sampled and were analyzed for Cd, Cu, Pb, and Zn extracted with different solution. Total heavy metal contents in both minewaste and bottom sediments were fairly high. Cadmium and Zn contents in the minewaste and Cd, Cu, Pb, and Zn contents in the bottom sediments extracted with 0.1 N HCl showed a much higher level than those in the background level of paddy soils and in the soils around the other metal mines regardless of the distance from the mine. Sulfide/residue forms of Cd, Cu, Pb, and Zn covered the highest portions for the minewaste. For bottom sediments, sulfide/residue forms of Cu and Zn formed the highest portions, whereas the contents of both carbonate and sulfide/residue forms of Cd and Pb were significant. The lower the pH of the extracting solutions, the more heavy metals extracted from both minewaste and bottom sediments.

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Possible Influence of Western North Pacific Monsoon on Tropical Cyclone Activity Around Korea (북서태평양 몬순이 한국 영향태풍활동에 미치는 영향)

  • Choi, Ki-Seon;Park, Ki-Jun;Lee, Kyungmi;Kim, Jeoung-Yun;Kim, Baek-Jo
    • Journal of the Korean earth science society
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    • v.36 no.1
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    • pp.68-81
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    • 2015
  • In this study, the correlation between the frequency of summer tropical cyclones (TC) affecting areas around Korea over the last 37 years and the western North Pacific monsoon index (WNPMI) was analyzed. A clear positive correlation existed between the two variables, and this high positive correlation remained unchanged even when excluding El Ni$\tilde{n}$o-Southern Oscillation (ENSO) years. To investigate the causes of the positive correlation between these two variables, ENSO years were excluded, after which the 8 years with the highest WNPMI (positive WNPMI phase) and the 8 years with the lowest WNPMI (negative WNPMI phase) were selected, and the average difference between the two phases was analyzed. In the positive WNPMI phase, TCs usually occurred in the eastern waters of the tropical and subtropical western North Pacific, and tended to pass the East China Sea on their way north toward Korea and Japan. In the negative WNPMI phase, TCs usually occurred in the western waters of the tropical and subtropical western North Pacific, and tended to pass the South China Sea on their way west toward the southeastern Chinese coast and the Indochina peninsula. Therefore, TC intensity was higher in the positive WNPMI phase, during which TCs are able to gain sufficient energy from the sea while moving a long distance to areas nearby Korea. TCs also tended to occur more often in the positive WNPMI phase. In the difference between the two phases regarding 850 and 500 hPa streamline, anomalous cyclones were reinforced in the tropical and subtropical western North Pacific, while anomalous anticyclones were reinforced in mid-latitude East Asian areas. Due to these two anomalous pressure systems, anomalous southeasterlies developed in areas near Korea, with these anomalous southeasterlies playing the role of anomalous steering flows making the TCs head toward areas near Korea. Also, due to the anomalous cyclones developed in the tropical and subtropical western North Pacific, more TCs could occur in the positive WNPMI phase.

A Study on the Bioavailability of Organic Ca in Growing Rats (성장기 흰쥐에서 유기태 칼슘의 체내 이용성 연구)

  • Park, Mi-Na;Cho, Su-Jung;Kim, Hee-Kyong;Kim, Jae-Hong;Kim, Min-Ho;Kim, Wan-Sik;Lee, Yeon-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.1
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    • pp.87-94
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    • 2012
  • We evaluated the bioavailability of a novel organic Ca supplement chelated with milk protein (CaMP) in growing rats and compared it with those of Ca carbonate and Ca citrate. Four-week-old male rats were divided into six groups (n=6/group) and fed AIN-93G-based experimental diets containing three Ca sources, Ca carbonate, Ca citrate, and CaMP at two levels, normal (0.5%, w/w) and high (1.5%, w/w), for 6 weeks. Growth, mineral contents of serum, Ca content and breaking force of femur, and Ca absorption were measured. There were no significant differences in weight gain or food intake, but food efficiency ratio (FER) of CaMP in the high Ca group was higher than those of other groups. Ca and P concentrations in serum were within normal range in all experimental rats. There was no difference in Ca content of the femur among all of the groups. Although there was no statistical significance in bone breaking force of the femur among the groups, the CaMP groups had a higher breaking force compared to other groups. Further, Ca absorption rate significantly increased in the CaMP groups (p<0.05). These results demonstrate that the CaMP supplement did not exhibit any negative effect on growth or Ca metabolism of the rats. Therefore, CaMP can be recommended as a good Ca supplement with regard to bone metabolism and Ca bioavailability.

Pollution of Pb in paddy field soil and rice plants at roadside areas;I. Pollution of Pb in paddy field soil and its chemical forms (도로변(道路邊)에 인접(隣接)한 경작지(耕作地) 토양(土壤) 및 작물체중(作物體重)의 연오염(鉛汚染) 제(第)1보(報) 경작지(耕作地) 토양중(土壤中)의 연오염(鉛汚染) 및 화학적(化學的) 형태(形態))

  • Lee, Seog-June;Kim, Jang-Eok
    • Korean Journal of Environmental Agriculture
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    • v.10 no.1
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    • pp.1-10
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    • 1991
  • The object of this stduy was to investigate the pollution of Pb in paddy field soil with different distance from roadside and to find out the relationship between the ratio of chemical fractions of total Pb and soil characteristics. Lead from automobiles is exhausted as particulates composed primarily of halide compounds (PbBrCl, $PbBr_2$, $PbCl_2$). The samples of soil were collected directly from the paddy fields with different distance from the roadside of highway and expressway which are located in Kyungpook province. A sequential extraction procedure was used to fractionate Pb in paddy field soil into the disignated forms of water soluable, exchangeable, organically bounded, carbonate, sulfide, and residual Pb. Results obtained are summerized as follows. 1. The content of Pb in paddy field soil was the highest in Chungdo, 30.0 ppm, the lowest in Koryung, 14.8 ppm, and the total average content was 21.9 ppm. The effect of traffic volume was not clear, but a slight difference according to the order of opened year of roads was showed. 2. The effect of distance from roadside was not clear. The content of Pb in paddy field soil with different distance from roadside was 22.2 ppm within l0m, 22.1 ppm in 10∼30m, 22.2 ppm in 30∼50m. and 21.3 ppm beyond 50m. 3. The distribution of Pb fractions in soil showed a wide difference depending on soil properties. The average content of exchangeable. organically bounded, carbonate, sulfide, and residual Pb was 8.6%, 33.6%, 29.8%, 21.5%, and 6.7%, of total Pb in the soil, respectively. 4. The content of organically bounded Pb in soil showed highly positive correlation with organic matter and CEC, while the content of exchangeable Pb was highly negative correlation. 5. With higher soil organic matter and CEC, organically bounded Pb fraction tend to be higher but exchangeable Pb fraction tend to be lower. Other forms of Pb showed no difference with soil organic matter contend and CEC. The distribution of Pb fraction related to CEC showed similiar tendency with that of organic matter content.

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정보통신사업 전개와 발전

  • Lee, Yong-Tae
    • The Science & Technology
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    • v.17 no.11 s.186
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    • pp.62-68
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    • 1984
  • 이 논문은 한국통신학회가 주최한 "정보통신심포지움"에서 이용태 박사가 발표한 요지이다

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