• 대한전자공학회논문지SD
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• 제41권1호
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• pp.15-20
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• 2004

산화막위에 증착된 금속박막과 산화막과의 계면효과를 조사하였다. 산화막으로는 현재 반도체소자제조공정에 많이 사용되고 있는 BPSG 산화막과 PETEOS 산화막을 사용하였다. 이 두 종류의 산화막위에 적층구조의 금속박막을 형성한 후, 금속박막의 열처리에 의한 계면의 영향을 SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy)를 사용하여 조사하였다. BPSG 산화막위에 증착된 금속박막을 $650^{\circ}C$ 이상에서 RTP anneal을 한 경우, BPSG 산화막과 금속박막의 계면결합상태가 좋지 않았고, BPSG 산화막과 금속박막의 계면에 phosphorus가 축적된 영역을 확인하였다. 반면에 PETEOS 산화막위에 증착된 금속박막의 경우, RTP anneal 온도에 관계없이 계면결합상태는 좋았다. 본 연구에서 BPSG 산화막위에 금속박막을 증착할 경우 RTP anneal 온도는 $650^{\circ}C$ 보다 작게 하여야 함을 알 수 있었다.

• The Korean Journal of Ecology
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• 제22권3호
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• pp.131-137
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• 1999

금호강(영천, 침산교, 팔달교, 달서천, 금호교)에서 널리 군락을 이루고 있는 갈퀴나물의 무기물 및 중금속 함량과 질소고정 활성의 변화양상을 비교 분석하였다. 금호강변 토양은 하류로 갈수록 무기물과 중금속 함량이 증가되었고, 더불어 식물체에도 높은 축적량을 보였다. 갈퀴나물은 비오염지에 비해 오염지역에서 지하부에 비해 지상부가 크게 발달되어 높은 T/R비를 보이면서 군락을 형성하였다. 식물체의 함수량은 생육후기 지상부에서 다소 높게 나타났고, 단위 g당 엽록소함량이 비교적 높게 나타났다. 근류는 4월에 형성되어 6월에 비오염지의 0.3 g/plant에 비해 침산교, 팔달교, 달서천 및 금호교에서 각각 0.27, 0.24, 0.06 및 0.14 g/plant로 최대치를 보였고, 비오염지 영천에서 23.1 μmol. C₂H₄·g fw nodule/sup -1/·h/sup -1/을 보인 근류의 질소고정 활성도 각각 16.8, 15.4, 8.5 및 5.3 μmol. C₂H₄·g fw nodule/sup -1/·h/sup -1/로, 하류지역으로 갈수록 감소된 활성을 보였고, 달서천과 금호교에서 심각한 저해를 보였다. 갈퀴나물은 흡수한 중금속 (Zn, Cu, Fe, Pb 등)을 지하부에서 높은 함량을 유지하였고, 질소함량은 생육후기로 갈수록 초기에 비해 지상부는 감소되었으나 지하부에서 높은 값을 보였다. 한편, 식물체내 총중금속량은 높은 T/R비로 인해 지상부에서 높은 값을 보였다. 흡수한 Ca는 대부분 지상부로 이동시켜 지하부에서 높은 함량을 보인 금속류와는 대조를 이루었다. 결과적으로, 갈퀴나물은 지상부에 높은 Ca함량을 나타내고, 지하부에 높은 중금속함량과 함께 질소의 함량도 높게 유지하면서 오염된 지역에서 생장 적응하는 것으로 판단된다.

• 동아시아식생활학회지
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• 제13권4호
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• pp.293-304
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• 2003

This study was performed to investigate the effects of peking-duck extracts added with medicinal herbs(DJ) on the intoxication of heavy metals (Hg, Pb, Cd, As) in rats. Sprague-Dawley rats weighing 150$\pm$15g, were randomly assigned to groups: basal diet only in normal control group(NCG): basal diet and heavy metals without DJ injection in heavy metal control group(HMC); basal diet, heavy metals and DJ(3mg/ml) injection in heavy metal low duck-juice group(HMLD), basal diet, heavy metals and DJ(30mg/ml) injection in heavy metal middle duck-juice group(HMMD): basal diet, heavy metal and DJ(300mg/ml) injection in heavy metal high duck-juice group(HMHD). Hg and As was injected by 50ppm and Cd and Pb by 25ppm for 17days. Also DJ oral feeding was conducted for 28days. The result of this study were as follows: Food intake and body weight gain in heavy metal administered groups were lower than those of NCG. Liver, kidney and testis weights were not significantly different among 5 groups. GOT, GPT and BUN activities were significantly reduced in DJ treated groups as compared to HMC. DJ showed the suppressing effect on the accumulation of Hg, Pb and Cd in serum, liver and kidney. Fecal Hg and Cd excretions increased with DJ feeding. The results suggested that DJ may have some protective effects on Hg, Cd and Pb intoxication by reducing the accumulation in tissues and increasing excretion. This study also showed the effective way of using duck-extract and its application to the oriental medicine.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.268-269
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• 2008

Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples.

• ALGAE
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• 제18권4호
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• pp.349-354
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• 2003

This paper reports that the heavy metal accumulation in marine seaweeds. Algal samples collected from Korean coast were analyzed to determine the concentrations of Cu, Cd, Cr, Zn and Pb. In general, heavy metals were found to be concentrated in many kinds of Korean seaweeds. The concentration levels of accumulated heavy metals in the marine seaweeds was in the following order: Zn > Cu > Cr > Pb > Cd. The concentrations of the heavy metals in the seawater were the highest in Iyajin harbor. Sargassum horneri, a brown alga accumulated high concentrations of Cu (80.66 ${\mu}g{\cdot}g^{-1}$ dw) and Cr (31.54 ${\mu}g{\cdot}g^{-1}$ dw). The high concentrations of heavy metals were accumulated in the brown algae.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.377-378
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• 2008

Space charge formation in various glass materials under electron beam irradiation was investigated. Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples. Furthermore, the dependence of the polarity of accumulated charges on the component of glass materials is discussed by using the models of energy bands.

• Composites Research
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• 제13권4호
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• pp.1-10
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• 2000

SiC가 강화된 금속복합재료는 기존의 금속재료에 비하여 비탄성계수와 비강도가 높기 때문에 자동차 및 항공산업에 많은 응용이 기대되고 있다. 금속복합재료의 파손기구는 적용된 하중에 의한 미시적 손상의 축적에 의해 많은 영향을 받기 때문에 금속복합재료의 광범위한 응용을 위해서는 금속복합재료가 반복 하중을 받을 때 미시적 파손기구를 이해하는 것이 대단히 중요하다. 따라서 본 연구에서는 SiCp/A356 금속복합재료의 미시적 손상 축적을 모니터링 하기 위하여 초음파와 음향방출기법을 적용하였다. 반복하중의 증가에 따라 초음파의 속도와 감쇠의 변화는 각 미시적 손상기구에 따라 3영역으로 나눌 수 있었다. 또한 각 영역에서 발생하는 AE 신호의 특징은 초음파의 속도 및 감쇠 변화와 비교, 분석되었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.158.2-158
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• 2003

No Abstract, See Full Text

• Journal of the korean society of oceanography
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• 제37권4호
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• pp.232-241
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• 2002

The potential role of environmental factors on extractable lipofuscin accumulation rate in the blue crab was studied by examining the effect of temperature on laboratory reared blue crabs and the effect of trace metals from samples collected at impacted sites (Baltimore Harbor) and a relatively pristine site (outdoor ponds at Horn Point Laboratory, Cambridge, MD, USA). Lipofuscin levels did not significantly related with sampling sites or heavy metal concentrations in the crab tissue. Heavy metal body burden was highly variable among sampling sites and tissue types but significantly higher for both impacted areas (Curtis Creek and Inner Harbor) in comparison to the reference site. Among tissue types, gills showed the highest metal concentrations with the exception of Hg, which was highest in muscle tissue. For two groups of crabs that were held at either ambient (4 to 1$0^{\circ}C$) or heated seawater (19$^{\circ}C$) for two months, normalized-lipofuscin levels were significantly different (P-0.001). Results suggest that temperature may affect lipofuscin accumulation (=0.25ng-lipofuscin/mg-protein/temperature-degree day). Therefore, temperature should be considered for accurate age calibration of crab populations using lipofuscin.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.28-32
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• 2000

There are many different chemical pollutants that originate from atmospheric deposition and transportational activities along roads. This paper review the characteristics of heavy metal pollution, relationships between land use and pollutant load in urban area. Four land use areas in Seoul were selected for sampling and study with different characteristics during the period from April 1998 and February 2000. A series of studies have been carried out concerning the physicochemical characteristics of the sediments settling down in a gully pot to evaluate the contamination for heavy metals. The sediment samples from gully pots were characterized by the chemical extraction experiments. Sediments are characterized by very high concentrations of heavy metals, probably because of a long-term accumulation of vehicle- and industrial-related pollutants. The characteristics of heavy metal pollution show that each land use has different sources of contaminations. Mean Zn concentration in Yeouido and Junggu areas is 2-3 times higher than those in Dobonggu area. This suggests that Zn may be derived from the source of automobile traffic. The mean concentrations of Cu and Cr are very significantly high in Junggu and Gurogu areas and indicate that the industrial activities may contribute to the accumulation of Cu and Cr in sediments. The low Pb levels throughout the whole study areas in Seoul can be accounted for the use of unleaded gasoline since 1987.