• Title/Summary/Keyword: Cu contents

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Studies on Particle Size Distribution of Heavy Metals in the Atmosphere (大氣中 重金屬의 粒經分布에 關한 硏究)

  • Sohn, Dong-Hun;Kang, Choon-Won
    • Journal of Korean Society for Atmospheric Environment
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    • v.2 no.3
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    • pp.57-63
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    • 1986
  • Atmospheric particulate matter (A.P.M.) was collected on quartz fiber filters from March 1985 to May 1986 according to particle size using Andersen high-volume air sampler, and 6 heavy metals (Fe, Mn, Cu, Ni, Zn, Pb) in these particulates were analyzed by atomic absorption spectrophotometry. The arithmetic mean concentration of A.P.M. was 195.57$\mug/m^3$. The arithmetic mean concentrations of 6 metals (Fe, Mn, Cu, Ni, Zn and Pb) were 3385.04, 1451.67, 897.94, 159.68, 127.14 and 59.49 $ng/m^3$ respectively. The order of heavy metals contributing to A.P.M. was as follows: Fe > Zn > Pb > Cu > Mn > Ni. These heavy metals were devided into 3 groups according to their particle size distribution. The contents of heavy metals belonging to the 1st group (Fe, Mn) were increased with the particle size. On the contrary, the content of Pb belonging to the 2nd group (Pb) was increased with the decrease in the particle size. The heavy metal contents in the 3rd group (Ni, Cu, Zn) were lowest in the particle size range of 2.0-3.3 $\mum$ compared with particles larger or smaller tha this range. The seasonal variation of heavy metal concentration were as follows: Fe and Mn contents were highest in spring, but Ni and Pb contents were highest in winter. Statistical analysis showed that there was a significant correlation between A.P.M. and Fe in coarse particles, meanwhile between A.P.M. and Pb in the case of fine particles.

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Physico-Chemical Properties and Composition of Venison in Deer Breeds. (사슴 품종별 녹육의 이화학적 특성에 관한 연구)

  • 이길왕
    • Journal of Life Science
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    • v.14 no.3
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    • pp.525-530
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    • 2004
  • This study has been performed to examine physico-chemical properties and composition of venison in Deer breeds. According the results, moisture content in the venison ranged between 74% and 75%, and there were no significant differences among the breeds, or among the cutting parts. Fat content in the meats was estimated as less than 1% except in loin, protein contents was estimated as more than 22%, and ash content was estimated as more than 1.5%. For the contents of inorganic material in the loin, Fe$^{3+}$ content was higher in Elk than in other breeds, the contents of $Cu^{2+}$, $Mn^{2+}$, $K^{+}$, $Mg^{2+}$ and $Ca^{2+}$were higher in Red deer than in others, and the contents of $Fe^{3+}$, $K^{+}$, and $P^{+}$ were higher in Sika deer than in others. For the contents of inorganic material in the leg, the contents of $Cu^{2+}$, $Zn^{2+}$, $K^{+}$, $Ca^{2+}$ and $Mg^{2+}$ were higher in Elk than in other breeds, the contents of $Fe^{3+}$ and$P^{+}$ were higher in Red deer than in others, and the contents of $Cu^{2+}$ and $Fe^{3+}$were higher in Sika deer than in others. Amino acid contents in the venison alanine, proline, glycine, lycine and histidine were highly contained. and the contents of asparagine, cysteine, isoleucine and threonine were low. For the differences of amino acid contents among the breeds, the level was the higher in Sika deer than those of others. For the fatty acid in loin, the contents of myristic acid, oleic acid and linolenic acid in Sika deer were higher than those of others, the contents of myristic acid, palmitoleic acid, oleic acid and arachidonic acid in Red deer were higher than those of others and in Elk, the contents of palmitic acid and stearic acid were higher than those of others. For the contents of unsaturated fatty acid and polyunsaturated fatty acids, the level was higher in Red deer than those of others. For the fatty acid in leg, the contents of oleic acid, linolenic acid, linolenic acid and arachidonine acid in Sika deer were higher than those of others, the contents of myristic acid, palmitic acid, palmitoleic acid and oleic acid in Red deer were higher than those of others and in Elk, the contents of stearic acid and linolenic acid were higher than those of others. For the contents of saturated fatty acid, the level was lowest in Sika deer. For the contents of unsaturated fatty acid and polyunsaturated fatty acids were respectively highest in Sika deer. Comparing the contents inorganic materials between loin and leg, the concentrations in leg were generally higher than that of loin.n.

Some DTPA Extractable Micronutrients in Different Hill Forest Soils of Chittagong Region, Bangladesh

  • Akhtaruzzaman, Md.;Osman, K.T.;Sirajul Haque, S.M.
    • Journal of Forest and Environmental Science
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    • v.32 no.1
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    • pp.20-26
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    • 2016
  • DTPA (Diethelene-triamine pentaacetic acid) extractable micronutrients of surface soil samples from six different locations of Cox's Bazar and Chittagong districts were studied. All the soils under study were sufficient in DTPA extractable Fe, Mn and Cu contents. The available Zn contents in soils of Dulhazara, Chengchhari and Faissakhali under study were also above the critical limit while soils at Fulchhari, Hasnabad and CU were deficient in available Zn. The study also showed that DTPA extractable Fe content had the significant and positive relationships with clay and soil organic carbon. On the hand, negative and significant relationship was observed between extractable Mn and soil pH while DTPA extractable Zn and Cu were positively and significantly correlated with soil organic carbon of the studied area.

우리나라 토양의 중금속 배경농도 및 특성 조사

  • Kim Dong-Ho;Kim Tae-Seung;Yun Jeong-Gi;Jeon Seong-Hwan;Jeong Il-Rok;Kim Jong-Ha
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.6-8
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    • 2005
  • The forest soils of 92 sites in Korea were analyzed to survey heavy metal background levels using aqua regia digestion method and 0.1N HCl extraction method. From these results, the average natural contents of heavy metals were Cd 0.287, Cu 15.26, Pb 18.43, Cr 25.36, Zn 54.27, Ni 17.68mg/kg for aqua regia method, and Cd 0.040, Cu 0.48, Pb 3.06, Cr 0.09, Zn 1.54, Ni 0.27mg/kg for 0.1N HCl extraction method. The range of correlation coefficients between heavy metal contents obtained from two methods(aqua regia and 0.1N HCl) was significant as $0.24{\sim}0.88$, and the correlation coefficients were decreased in order of Cd, Pb, Cu, Ni, Cr, Zn.

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The Effect of Ti and Sn Contents on the Shear Bonding Strength of Brazing Joint of YSZ to STS430 using Ag Based Filler Metals (Ag계 Filler Metal을 사용한 YSZ와 STS430의 브레이징 접합시 Ti, Sn의 함량 변화가 접합강도에 미치는 영향)

  • Lee, Ki Young;Park, Hyun Gyoon
    • Journal of Welding and Joining
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    • v.32 no.1
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    • pp.66-70
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    • 2014
  • In Ti active brazing of YSZ to STS 430 using Ag-Cu Filler Metal, the effect of Ti contents on the shear bonding strength were investigated together with the effect of brazing temperature and holding time. The addition of Ti in Ag-Cu Filler Metal increased the bonding strength up to 4.68% Ti, followed by the decrease with further addition. This seems to be caused by formation of TixOy at the reaction layer. Brazing temperature was optimized at $960^{\circ}C$ among a given temperature ranges. The addion of Sn to Ag-Cu filler metal brought the decrease of its melting temperature its melting temperature without a significant decrease of bonging strength.

Distribution of Cadmium, Copper, Lead, and Zinc in Paddy Soils around an Old zinc Mine (가학광산 주변 논토양의 카드뮴, 구리, 납 및 아연 함량 분포)

  • 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.424-431
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    • 1996
  • This study was carried out to provide information for establishing counter measures of soil pollution through analysis of Cd. Cu, Pb, and Zn in paddy soils and brown rice. Cadmium, Cu, Pb, and Zn contents in soils were analyzed and distribution maps for these heavy metals were prepared. Heavy metal contents in brown rice were also measured. Average contents of Cd, Cu, Pb, and Zn in surface paddy soils extracted with 0.1 N HCl were 7.4, 35.8, 98.9, and $118.8mg\;kg^{-1}$, respectively. These were 9 times (Cu) to 50 times (Cd) higher than the background level of heavy metals in unpolluted paddy soils in Korea. The contents of Pb and Zn were lower than those measured in 1980, whereas Cd content did not decrease. The levels of heavy metal contamination in paddy soils may not affect growth or yield of rice plant, however, Cd contents indicated a level of serious concern to humans. The average contents of Cd, Cu, Pb, and Zn in brown rice were 0.38, 2.38, 1.31 and $22.31mg\;kg^{-1}$, respectively.

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Dispersion of Toxic Elements in the Area Covered with Uranium-Bearing Black Shales in Korea (함(含)우라늄 흑색(黑色)세일 분포지역(分布地域)에서의 유독성원소(有毒性元素)들의 분산(分散)에 관한 지구화학적(地球化學的) 연구(硏究))

  • Chon, Hyo-Taek;Jung, Myung-Chae
    • Economic and Environmental Geology
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    • v.24 no.3
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    • pp.245-260
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    • 1991
  • Surficial dispersion patterns of heavy metals and toxic elements (U, Mo, Cu, Zn, Fe, Mn, Co, Cr, V, Ni, Pb, and Cd) were investigated in the Dukpyungri, Goesan area covered with low grade uranium-bearing black shales. Maximum abundance of U in the black shale was 455ppm. Radioactivity was counted at a maximum of 7cps in black shales, and was less than 0.5cps in shales, slates, and oil shales of the control areas. Enrichment of Mo, V, Cu, Zn, Cd, and Pb in black shales is particularly characteristic compared with shales, slates, and oil shales of the control areas, whereas contents of Mn, Cr, Co, and Th in all rock samples tend to be almost similar. Residual top soils (0~15cm depth) over black shales show high contents of Mo, Cu, Zn, Ni, Cd, and V in comparison with the control areas. Contents of trace elements in subsoils (15~30cm depth) were higher about one and half times than those in topsoils. Average contents of Mo, Cu, Pb, Zn, Cd and V in garden soil and playground soil of an elementary school in Dukpyungri, Goesan area, were high about two to fifteen times compared with the control areas. Contents of trace elements in stream sediments were higher from two to eight times than those in residual soils. Sodium, AI, K, V, Cr, and Fe were more enriched in the roots of pine than in the twigs of pine. Contents of Li, AI, V, Ni, Cd, Fe, and Co were higher in the roots of azalea than in the twigs of azalea. Enrichment of P, Ca, and Mg was remarkable in the twigs of both pine and azalea. Biological absorption coefficients for essential elements (Zn, P, Mn, Ca and K)tend to be high, whereas those for the non-essential elements.(Ba, Ti, V, and Mo) and toxic elements(Cr, Co, Pb and Ni) be low. Less mobile elements (Pd, Cd, and Co) tend to show anomalies with higher contrast than more mobile elements(Mo, V, Zn, Cu and Ni) in the area covered with black shales.

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High $T_c$, Superconductors for Applications

  • Soh, Deawha;Fan, Zhanguo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.366-369
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    • 2003
  • High T$_{c}$ superconducting lines will be applied as key materials in the areas of power transmission line; magnetic levitation of vehicle; magnetic separation; magnetic energy storage and marine propulsion. A combination method of electrophoresis deposition and zone-melting for preparation of YBaCuO tape is proposed. The submicron particle powder of YBaCuO made by sol-gel method is used in the electrophoresis process. A 40~50${\mu}{\textrm}{m}$ thickness of YBaCuO film on Ag plate could be deposited in about three minutes. After deposition the film is rolled and heat treated in order to increase the density and the adhesion of the film to the Ag plate. Silver(Ag) and lead oxide(PbO) were added in the YBaCuO powder in order to reduce its melting point. The YBaCuO coating with controlled Ag and PbO contents was preliminarily zone-melted at about 945$^{\circ}C$.>.

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Manufacturing of W-Cu and Mo-Cu Sheet by Tape Casting Method (Tape Casting법을 이용한 W-Cu, Mo-Cu 박판소재 제조)

  • Park, Chi-Wan;Jang, Gun-Eik;Kim, Tae-Hyoung;Woo, Yong-Won
    • Journal of the Korean Society for Heat Treatment
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    • v.17 no.5
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    • pp.293-298
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    • 2004
  • For the application of heat sink device, the green sheets of powder of W-XCu and Mo-XCu composites were fabricated by tape casting technique. The mixing ratio of powder and binder was 6:4. The green sheet was shrinked up to 10~20% after sintering and the maximum relative density was above 95%. Thermal conductivity and Thermal expansion systematically increased with increasing Cu contents. The maximum thermal conductivity of W-20wt.%Cu was about 206[W/mK].

High $T_c$ Superconductor Applications and Thick Film Preparation

  • Soh, Dea-Wha;Zhanguo Fan
    • Journal of information and communication convergence engineering
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    • v.1 no.2
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    • pp.63-66
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    • 2003
  • High $T_c$ superconducting lines will be applied as key materials in the areas of power transmission line; magnetic levitation of vehicle; magnetic separation; magnetic energy storage and marine propulsion. A combination method of electrophoresis deposition and zone-melting for preparation of YBaCuO tape is proposed. The submicron particle powder of YBaCuO made by sol-gel method is used in the electrophoresis process. A 40∼50 ${\mu}\textrm{m}$ thickness of YBaCuO film on Ag plate could be deposited in about three minutes. After deposition the film is rolled and heat treated in order to increase the density and the adhesion of the film to the Ag plate. Silver(Ag) and lead oxide(PbO) were added in the YBaCuO powder in order to reduce its melting point. The YBaCuO coating with controlled Ag and PbO contents was preliminarily zone-melted at about $945^{\circ}C$.