• 한국표면공학회지
• /
• 제51권5호
• /
• pp.263-270
• /
• 2018

Ag-coated Cu dendrites were prepared as a filler for an electromagnetic interference shielding application. Ag layers on the Cu dendrites was coated by two approaches. One is a direct autocatalytic plating with a reducing agent. The other approach was achieved by two-step plating, a galvanic displacement reaction to form Ag seed layers on Cu following by an autocatalytic plating with a reducing agent. The procedure-dependent average particle size and tap density of Ag-coated Cu dendrites were characterized. The electrical resistance and electromagnetic interference shielding effect (EMI SE) were analyzed with the Ag-coated Cu dendrites prepared in the two approaches. Additionally, the content of the Ag coated on Cu dendrites was controlled from 2% to 20%. The electrical resistance and EMI SE were critically determined by Ag contents coated on Cu.

• Journal of Plant Biology
• /
• 제23권2호
• /
• pp.55-60
• /
• 1980

The quantity of heavy metals (As, Cd, Cu, Pb, Zn) contained in marine algae collected in Onsan-myon on the east coast of Korea from March to December 1978 was determined as a part of the environmental base line survey of the Onsan Industrial Base. In general, green algae have a higher Cu content than either brown or red algae, and brown algae have higher As and lower Cu contents, while red algae have a higher Zn content. Significant differences between algal species in either Cd or Pb content were however not found.

• 한국주조공학회지
• /
• 제39권6호
• /
• pp.103-109
• /
• 2019

Cu-added SKD11 was manufactured through the casting process and the effects of Cu addition with different contents (0, 1, 2 and 3 wt%) and aging treatment on microstructure, mechanical characteristics such as tensile strength and hardness, and thermal conductivity were investigated. The microstructure was analyzed by FE-SEM and XRD, the mechanical characteristics by Rockwell hardness tester and Tensile tester, and the thermal conductivity by Laser flash. As a result, SKD11 containing Cu had higher hardness than as-received SKD11. The hardness of as-cast SKD11 containing 1 wt% Cu was 42.4 HRC, whereas the hardness of asreceived SKD11 cast alloy was 19.5 HRC, indicating that the hardness was greatly improved when Cu was added. In the case of tensile strength, Cu-added SKD11 cast alloy had lower tensile strength than as-received SKD11, and the tensile strength tended to increase as Cu content increased. After heat treatment, however, tensile strength of as-received SKD11 was significantly increased, whereas in the case of Cu-added SKD11, as the Cu contents increased, the tensile strength increased less and even reduced at 3 wt% Cu. The thermal conductivity of Cu-added SKD11 cast alloy was about 13 W m^-1 K^-1, which was lower than that of the asreceived SKD11 cast alloy (28 W m^-1 K^-1). After the heat treatment, however, the thermal conductivity of as-received SKD11 was reduced, while the thermal conductivity of the SKD11 added with Cu was increased. Thermal conductivity was generally larger with less Cu content, and this tendency became more pronounced after heat treatment.

• 환경위생공학
• /
• 제2권3호
• /
• pp.31-38
• /
• 1987

Bean sprouts is one of the popular traditional foodstuffs as a subsidiary articles of diet in Korea. As the need arise from restaurents, bean sprouts were produced by forcing culture in manufacture. In oder to prevent of the hazard' by trace metals such as Hg, Cd, Pb, Cu and Zn, the contents of these metals were analyzed. Hg, Cd, and Pb were not . detected , but the mean contents of Cu and Zn were O.33ppm and 0.356 ppm, respectively. It seems that the higher oontents of Cu and Zn in beas sprouts was the results of relative high concentration of itself. These contents has no problean in now, but the more sanitary management in manufacture and in bean producing region will be needed.

• 한국토양비료학회지
• /
• 제30권2호
• /
• pp.152-160
• /
• 1997

우리나라 전국 주요 시설재배지 토양을 표토 0-15cm와 심토 15-30cm 깊이로 구분하여 522점의 시료를 채취하고 중부지역에서 채소류 147점을 수확기에 채취하여 이들 토양 및 채소시료중에 함유된 Cd, Cu, Pb, Zn 및 As 함량을 조사한 결과를 요약하면 다음과 같다. 토양중 0.1N-HCl 가용성 중금속의 평균함량은 카드뮴 0.208(0.027~0.605), 구리 3.69(0.18~31.37), 납 2.49(0.02~33.55), 아연 23.3(2.1~113.2), 비소 0.65(0.03~2.2)mg/kg 이었다. 시설재배지 토양의 중금속 함량은 모두 '89년 조사한 일반 밭토양 자연함량보다 높은 함량을 보였고, 특히 카드뮴 및 아연함량이 시설재배지에서 높게 나타났다. 또한 시설 경작년수가 증가함에 따라 카드뮴, 구리 및 아연함량이 증가하였고 퇴비종류별로는 돈분퇴비 시용농가에서 높은 함량을 보였다. 그러나 시설재배지 토양의 중금속함량은 토양환경보전법의 토양오염 우려 및 대책기준과 비교하여 매우 낮은 함량수준으로 나타나 작물재배에 안전한 수준이었다. 채소 생체중의 중금속 평균함량은 카드뮴 0.015~0.047, 구리 0.341~0.802, 납 0.080~0.356, 아연 1.08~8.04, 비소 0.021~0.059mg/kg 으로 나타나 카드뮴 및 납의 경우 EU의 채소류 식품검토안(Cd : 0.10mg/kg, Pb : 0.50 mg/kg) 이하로 안전한 수준이었다.

• 분석과학
• /
• 제19권4호
• /
• pp.342-351
• /
• 2006

서울시내에 유통 중인 대형어류 17종 89건에 대하여 원자흡광광도계(AAS) 및 수은분석기 등을 이용하여 납, 카드뮴, 수은, 크롬, 구리, 비소 함량을 근육, 간 및 아가미 등의 부위별로 분석하였다. 그 결과를 요약하면 다음과 같다($Mean{\pm}SD$, mg/kg). 어종별 평균 중금속 함량은 Hg $0.08{\pm}0.01mg/kg$, Pb $0.17{\pm}0.32mg/kg$, Cd $0.34{\pm}0.07mg/kg$, Cr $0.05{\pm}0.05mg/kg$, Cu $1.14{\pm}0.13mg/kg$, As $0.24{\pm}0.22mg/kg$ 이었다. 부위별 유해 중금속의 전체적인 측정치를 살펴보면 중금속과 어종에 상관없이 간의 측정치가 가장 높게 나타났다. 나라별 중금속을 비교한 결과 Hg, Pb, Cu는 뉴질랜드산, Cd, As는 노르웨이산, Cr은 국내산 어류의 평균함유량이 다른 나라 어류보다 다소 높은 측정치를 보였으나, 자연함량수준으로 오염의 가능성은 없다고 생각된다. 기준초과로 검출된 어종은 일본에서 수입된 황돔으로 두 건이었다. 어류의 간과 근육 부위 중금속 함량 간의 상관관계는 Hg (r=0.989, p<0.01), Pb (r=0.978, p<0.01), Cd (r=0.991, p<0.01), Cu (r=0.998, p<0.01), As (r=0.198, p<0.05)에서 상관관계를 나타냈으며, Cr (r=0.082)은 유의적 상관관계가 인정되지 않았다.

• Journal of Preventive Medicine and Public Health
• /
• 제21권2호
• /
• pp.320-328
• /
• 1988

This study was carried out to investigate the heavy metal contents and their correlationship between paddy soil and brown rice near the Kum-River area. In this study, eighty soil samples and forty brown rice samples were taken from the paddy soil. The contents of heavy metals were measured by flame atomic absorption spectrophotometry. The results were as follows: 1. The average contents of soluble heavy metals in surface soil were Cd 0.19, Cu 15.31, Zn 18.10 and Pb 9.08 ppm. The average contents of soluble heavy metals in subsurface soil were Cd 0.19, Cu 14.52, Zn 17.75 and Pb 8.11 ppm. There was no statistically significant difference between the two layers. 2. The contens of Cu, Zn and Pb of Taejeon(S6) and Cd of Sinbyung(S5) in surface soil were higher than those of other areas. The contents of Cd and Cu of Taejeon(S6) and Zn and Pb of Kumnam(S3) in brown rice were higher than those of other areas and four heavy metals in soil and brown rice of Simchon(S7) were lower than those of other areas. 3. The ratio of soluble contents(Cd:Cu:Zn:Pb) in surface soil was 1:79:93:47, that of soluble contents in subsurface soil was 1:76:94:43, and that of total contents in brown rice was 1:84:294:12. 4. The correlationship of the content between soluble heavy metals in surface(0-15 cm depth) soil total heavy metals in brown rice was found to be order of Cd>Cu>Zn>Pb. The correlationship of the content between soluble heavy metals in subsurface(20-30 cm depth) soil and total heavy metals in brownricewasfoundtobeorderofcu>Cd>Zn>Pb.

• Nutrition Research and Practice
• /
• 제8권4호
• /
• pp.439-444
• /
• 2014

BACKGROUND/OBJECTIVES: Korean ordinary diets are referred to be good for human health in worldwide. However it is uncertain whether they provide microminerals enough for growth and health of teenagers. A main purpose of this study was to identify micromineral contents in school meals. MATERIALS/METHODS: The fifty cuisines were collected from elementary schools and middle schools in Gyeongnam area. The contents of Fe, Zn, Cu and Mn among microminerals were analyzed by using ICP-OES method. Data were expressed as mean, standard deviation and range value and linear regression analysis performed. RESULTS: Fe level of Pangibuseotpaprika-salad was the highest among side-dishes (average $346.6{\mu}g$) and Zn level of Sullung-tang was highest among soups (average $229.1{\mu}g$). Cu level of Buchu-kimchi was the highest among kimchies (average $217.5{\mu}g$) and Mn level of Gumeunkongyangnyum-gui was highest among side-dishes (average $198.4{\mu}g$). Generally cooked-rices as main dish had relative smaller amounts of microminerals than the other cuisines. The results showed that the ratio of Cu : Fe : Zn was approximately 12 : 4 : 1 and the relationship between Fe versus Zn or Fe versus Cu was significantly positive. CONCLUSION: Comparing to Korean Dietary Recommended Intakes (KDRI) level, school meals provided not sufficient amount (<25% DRI) of Fe, Zn or Mn, while they did excessive amount (>125% DRI) of Cu.

• 한국초지조사료학회지
• /
• 제20권2호
• /
• pp.109-114
• /
• 2000

The aim of present research was to know Cd availability. As a first report of this work, we present some results of analysing soil Cd and Cu contents on a part of Burgundy in France. Soil samples were collected from surface-ploughed layer in fields across the southern part of the Yonne district, Burgundy, France. From the first extractable Cd content on a ratio (soil : EDTA =1:10), the soil Cd values on Carixien soil series decreased to a-third or to a-fourth of those Cd values on a lower ratio (soil : EDTA = 15). While the extractable Cd of the soil samples on Sols marron soil series decreased in a smaller extent. The changes of mixing ratio from 150 (soil : EDTA) to 1:10 and to 1:5 (soil : EDTA) had decreased the extractable Cu contents. But the range of the decrease was not so large as that of Cd contents. Soils on some soil series were a half (Carixien) or two-thirds level (Dombrien, Aubes) when comparing the extractable Cu content on 1:5 ratio to the content on 150 ratio. The absorbance for Cu analyses of soils on Carixien, Terres noires, Sols marron soil series varied in larger extent (expressed on standard deviation for 6 values) than that of soils on Dombrien, Aubes soil series.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
• /
• pp.242-246
• /
• 2006

Background level of heavy metals In soils (316 points by 15 classifications of land use) was investigated by two test methods, 0.1N HCl(1N HCl for As) extraction and aqua regia extraction methods. The average concentrations of aqua regia extractable heavy metals in soil(n=316) was 6.24(As), 0.25(Cd), 37.99(Cr), 24.10(Cu), 0.04(Hg), 25.68(Pb), 22.59(Ni), 106.11(Zn) mg/kg, respectively. Also the average concentrations of 0.1N HCl extractable heavy metals was 0.06(As), 0.08(Cd), 0.27(Cr), 3.78(Cu), 4.02(Pb), 12.5(Zn), 0.58(Ni) mg/kg, respectively. The ratio of soluble contents and total contents were 2.6%(As), 32.7%(Cd), 0.7%(Cr), 15.7%(Cu), 15.7%(Pb), 2.6%(Ni), 11.8%(Zn), and the correlation coefficient of soluble contents and total contents were 0.26(As), 0.27(Cd), 0.22(Cr), 0.57(Cu), 0.42(Pb), 0.23(Ni), 0.72(Zn).