• 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 $945^{\circ}C$.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.19-23
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• 1993

This study was conducted to investigate contents of inorganic constituents, free sugars and catalpol in the Rhizoma of Rehmannia glutinosa as different growth stages. With the approach of harvesting season, the variations of their contents were as follow. The contents of P, K, Ca, Mg, Cu and ash in the Rhizoma decreased, whereas the contents of Fe, water and ethanol extract increased. The contents of total sugar, sucrose and galactose in the Rhizoma decreased, but the fructose and catalpol contents in the Rhizoma were increased.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.51-56
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• 1986

In the particular area the heavy metal concentrations in the soil were determined and compared to the contents in vegetables which were grown on the soil. Simultaneously the degree of contamination was examined. Samples were collected from Chinese cabbage, radish and Altari-mu, together with the soil on which the three kinds of vegetables have grown. The sites of samples collection were Jinguan-sa(non-polluted area) and Sangaedong(polluted area). The contents of cadimium, copper, lead and zinc were determined by means of atomic absorption spectro-photometer. The results obtained were as follows; 1. In soils, the average contents of heavy metal in Jinguan-sa area (Cd; 0.15ppm, Cu; 0.15ppm, Zn; 11.5ppm) were lower than those in sangye-dong(Cd; 0.26ppm, Cu; 13.0ppm, Zn; 17.1ppm). 2. In vegetables, the average have metal contents in Jinguan-sa were cadmium; 0.11ppm, copper; 5.29ppm, zinc; 18.75ppm and the average contents in Sangye-dong were cadmium; 0.16ppm, copper; 6.64ppm, lead; 0.14ppm, zinc; 15.01ppm. 3. The contents of lead showed zero ppm in Jinguan-sa area(soil and vegetables). In vegetables difference in concentration of heavy metals was not observed between reclaimed area and non reclaimed area. Statistical analysis showed that no correlation in the heavy metal concentrations between those in soils and in vegetables.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.45-52
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• 1994

This study was performed to investigate the contents of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) with respect to the particle sizes and depths in sediment collected at nine sites of the lower Kumho river. The mean Cd, Cr, Cu, Ni, Pb and Zn contents in sediment of all sites ranged from 1.59~5.32 mg/kg, 17.4~301.7 mg/kg, 23.2~399.9 mg/kg, 9.48~116.8 mg/kg, 31.1~294.1 mg/kg and 74.2~964.3 mg/kg, respectively. The highest heavy metal contents was generally found to be Zn and lowest was Cd. The mean contents of heavy metal by particle sizes (1.0~0.5, 0.5~ 0.25, <0.25 mm)was the highest in particle sizes less than 0.25 mm, but the coefficients of variation was lowest in particle sizes less than 0.25 mm. Mean contents and coefficient of variation by depths (0~5 cm, 5~10 cm, 10~15 cm) were generally found to be higher in the upper parts of sediment than in the lower parts of sediment. Organic substances were found to be higher as the particle sizes become more small. Moreover, contents of heavy metal increased with the amounts of organic substances in sediment.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.33.1-33.1
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• 2011

Strontium doped lanthanum manganite (LSM) with perovskite structure for SOFC cathode material shows high electrical conductivity and good chemical stability, whereas the electrical conductivity at intermediate temperature below $800^{\circ}C$ is not sufficient due to low oxygen ion conductivity. The approach to improve electrical conductivity is to make more oxygen vacancies by substituting alkaline earths (such as Ca, Sr and Ba) for La and/or a transition metal (such as Fe, Co and Cu) for Mn. Among various cathode materials, $LaSrMnCuO_3$ has recently been suggested as the potential cathode materials for solid oxide fuel cells (SOFCs). As for the Cu doping at the B-site, it has been reported that the valence change of Mn ions is occurred by substituting Cu ions and it leads to formation of oxygen vacancies. The electrical conductivity is also affected by doping element at the A-site and the co-doping effect between A-site and B-site should be described. In this study, the $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_{3{\pm}{\delta}}$ ($0{\leq}x{\leq}0.4$) systems were synthesized by a combined EDTA-citrate complexing process. The crystal structure, morphology, thermal expansion and electrical conductivity with different Sr contents were studied and their co-doping effects were also investigated.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.405-420
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• 2014

To investigate geochemical characteristics of soil and atmospheric environments by anthropogenic source, we have analyzed and determined heavy metal concentrations of the surface soils beneath roadside trees and leaves of Platanus occidentalis from 52 points in Seoul during autumn 2001. For comparison of the contents of heavy metal for the soil and leaf, we have analyzed heavy metal contents of the surface soils beneath roadside trees and leaves from 2 points in rural area of Yesan during the same time period. The composition of heavy metals of soils are relatively high for Cd, Co, Cr and Ni in industrial area (IA, Industrial Area) and high for Cu, Pb and Zn in heavy traffic area (HTA, Heavy Traffic Area). The heavy metal contents of rural area in Seoul are higher than those in Yesan. The differences of chemical compositions between the washed and unwashed leaves are high for Cd, Cu, Pb and Zn in the HTA. The element couples of Cd-Co, Cr-Ni and Pb-Zn for the soils had shown a good correlation and their contamination sources could be similar. The relationship for Pb-Cu and Cu-Zn showed good correlation in Platanus leaves. The relationship between soils and unwashed leaves show a good correlation for Cr, Cu, Pb and Zn but low correlation for Cd, Co, Fe, Mn and Ni. It is thought that the Cr, Cu, Pb and Zn were derived from contaminants of soils, whereas Cd, Co, Fe, Mn and Ni were originated from atmospheric source. From the spatial variations of elements for soils and leaves, Ni and Cr were dominant in the soils of IA and Cd, Cu and Zn were dominant in those of HTA. The Contamination by Cd-Pb and Cu-Zn in unwashed leaves were analyzed to show similar patterns. Using the enrichment factors (EF) of heavy metals in unwashed leaves, the EF sequences were to be Cu, Zn, Pb, Mn, Co, Ni, Cd and Cr. We identified that Cu, Zn, Pb and Mn were most problematic of environmental hazard in Seoul.

• Proceedings of the Korean Magnestics Society Conference
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• 1995.10a
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• pp.64-65
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• 1995

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.84-87
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• 2003

Since Pb-free solder alloys have been used extensively in microelectronic packaging industry, the interaction between UBM (Under Bump Metallurgy) and solder is a critical issue because IMC (Intermetallic Compound) at the interface is critical for the adhesion of mechanical and the electrical contact for flip chip bonding. IMC growth must be fast during the reflow process to form stable IMC. Too fast IMC growth, however, is undesirable because it causes the dewetting of UBM and the unstable mechanical stability of thick IMC. UP to now. Ni and Cu are the most popular UBMs because electroplating is lower cost process than thin film deposition in vacuum for Al/Ni(V)/Cu or phased Cr-Cu. The consumption rate and the growth rate of IMC on Ni are lower than those of Cu. In contrast, the wetting of solder bumps on Cu is better than Ni. In addition, the residual stress of Cu is lower than that of Ni. Therefore, the alloy of Cu and Ni could be used as optimum UBM with both advantages of Ni and Cu. In this paper, the interfacial reactions of Sn-3.5Ag-0.7Cu solder on Ni-xCu alloy UBMs were investigated. The UBMs of Ni-Cu alloy were made on Si wafer. Thin Cr film and Cu film were used as adhesion layer and electroplating seed layer, respectively. And then, the solderable layer, Ni-Cu alloy, was deposited on the seed layer by electroplating. The UBM consumption rate and intermetallic growth on Ni-Cu alloy were studied as a function of time and Cu contents. And the IMCs between solder and UBM were analyzed with SEM, EDS, and TEM.

• Journal of Nutrition and Health
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• v.17 no.2
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• pp.145-153
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• 1984

This study was performed to investigate the effect of various levels of Zn(0, 30, 3000 ppms) and different kinds of lipid(corn oil, sesame oil or butter.) in the diet upon lipid metabolism and Zn & Cu concentration in various organs and tissues in weanling rats. The results obtained were summarized as following : 1) Food consumptions, body weight gains and F.E.R.s showed no significant differences among groups. 2) The contents of total lipids and total cholesterols in serum tended to increase with increase in lipid saturation and Zn levels. Those in per g liver were higher in butter groups and tended to be higher in low Zn groups. Total lipids contents in per g muscle tended to be higher in butter and high Zn groups, but total cholesterols contents in per g muscle tended to be higher in corn oil and low Zn groups. 3) Liver, serum and fecal Zn concentrations tended to be higher in high Zn groups than other Zn groups. The Cu concentrations in liver and serum tended to be lower in high Zn groups. On the contrary, the Cu concentrations in urine tended to be higher in high Zn groups.

• Analytical Science and Technology
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• v.20 no.6
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• pp.524-528
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• 2007

Variations of the twenty one metal components (Mg, Al, V, Cr, Co, Sr, Ba, Na, K Mn, Fe, Cu, Zn, As, Hg, Pb, Ca, P, Mo, Cd, Sb) were analyzed in human hair sample by inductively coupled plasma mass spectrometry (ICP-MS). The effect of bleach and permanent wave manipulation on the elemental composition of hair were investigated. It was found that the composition of hair varied with hair bleach and permanent wave. Hair sample was collected from male in the age of thirties. Hair sample (0.05 g) was added to the Teflon digestion bomb together with 1.5 mL of nitric acid and an appropriate amount of In as an internal standard. The sample was then decomposed in the microwave digestion system. In normal hair, the contents of V, Cr, Mn, Fe, Co, Cu, Zn, As, Mo, Cd, Sb and P were increased in permanent wave hair, and Mg, Al, V, Co, Sr, Ba, Na and K were increased in bleached hair. But Mg, Al, Sr, Ba, Hg, Pb, Na, K, and Ca contents were decreased with permanent wave hair, Mn, Fe, Cu, Zn, As, Hg, Pb and Ca contents were decreased with bleached hair.