• 제목/요약/키워드: Lead(Pb)

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ECR PECVD법으로 증착된 lead titanate박막의 조성과 미세구조에 대한 증착변수의 영향 (The Effects of Process Parameters on the Composition and Microstructure of Lead Titanate Thin Films deposited by ECR PECVD)

  • 정수옥;정성웅;이원종
    • 한국재료학회지
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    • 제7권2호
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    • pp.93-101
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    • 1997
  • Lead titanate박막을 $Pt/Ti/SiO_{2}/Si(Pt/Ti기판)와\;Pt/Ta/SiO_{2}/SiO_{2}$Si(Pt/Ta 기판) 위에서 전자 사이크로트론 공명플라즈마 화학증착법(ECR PECVD)으로 증착하였다. 증착온도, 산소유입량, MO source유입비등의 증착변수에 따른 lead titanate박막의 조성과 미세구조를 주사전자현미경(SEM), 투과전자현미경(TEM), X선 회절법(XRD)으로 조사하였다. 산소유입량이 적을 경우,Tisource와 Pb source의 산소화의 반응성 차이 때문에 Pb 농도가 부족한 화학양론비가 잘 맞는 박막이 증착되었다. Pt/ti기판은 lead titanate박막증착도중 기판의 Ti층과 Pt층의 확산으로 기판변형이 발생하는 반면, Pt/Ta기판은 기판변형이 일어나지 않았다. Pt/Ta기판에서 페롭스카이트 화학양론비를 갖는 매우 평탄한 lead titanate박막을 증착 하였는데, 산소유입량이 lead titanate박막의 결정성을 크게 지배하였다.

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Protective effects of Hizikia fusiforme and Chlorella sp. extracts against lead acetate-induced hepatotoxicity in rats

  • Park, Joo hyun;Choi, Jeong-Wook;Lee, Min-Kyeong;Choi, Youn Hee;Nam, Taek-Jeong
    • Fisheries and Aquatic Sciences
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    • 제22권1호
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    • pp.2.1-2.9
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    • 2019
  • In the present study, the protective effects of Hizikia fusiforme and Chlorella sp. extracts on lead acetate-induced hepatotoxicity were investigated. Hepatic damage was induced in rats by intraperitoneal (i.p.) injection of lead acetate and the protective effects of H. fusiforme (HZK) and Chlorella sp. (CHL) extracts on lead acetate-induced hepatic damage in rat liver were examined. The results revealed significantly increased glutamic oxaloacetate and glutamic pyruvic transaminase levels in the group treated with lead acetate only (Pb group); oral administration of HZK and CHL extracts tended to decrease the enzyme levels similar to those observed in the control group. Regarding antioxidant enzymes, superoxide dismutase activity was increased in the Pb group and decreased in a concentration-dependent manner in the HZK- and CHL-treated groups. Glutathione levels were increased in a concentration-dependent manner in the HZK- and CHL-treated groups. There was no significant difference in catalase activity. Western blot analysis showed inflammation-related protein expression in mitogen-activated protein kinase and Nrf2 pathways was affected in the HZK- and CHL-treated groups. Therefore, HZK and CHL extracts exerted antioxidant and anti-inflammatory effects against lead acetate-induced hepatotoxicity. Development of functional health foods containing HZK and CHL extracts, which have hepatoprotective effects against inhaled lead acetate, should be considered.

농작물(農作物)에 대(對)한 납(Pb)의 흡수(吸收) 및 피해경감(被害輕減)에 관(關)한 연구(硏究) -III. 수도(水稻)의 납 흡수이행(吸收移行)에 대(對)한 물관리(管理) 및 석회물질(石灰物質)의 효과 (Studies on uptake of lead by crops and reduction of it's damage -III. Effect of water management and lime application on Pb uptake in paddy rice)

  • 김복영;김규식;한기학
    • 한국토양비료학회지
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    • 제19권4호
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    • pp.291-296
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    • 1986
  • 수도(水稻)에서 납(pb) 흡수양상(吸收樣相) 및 흡수경감효과(吸收輕減效果)를 구명(究明)하기 위(爲)하여 토양(土壤)에 납을 0, 150, 300, 600 ppm 으로 처리(處理)하고 소석회(消石灰) 및 규회석(硅灰石)을 시용(施用)하여 pot 재배(栽培)하고 수도(水稻)의 경엽(莖葉), 현미중(玄米中) 납함량(含量) 및 흡수량(吸收量)과 pH, 칼슘, 마그네슘함량(含量)과의 관계(關係)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 토양중(土壤中) 납처리농도(處理濃度)가 증가(增加)할수록 경엽(莖葉)과 현미중(玄米中) 납함량(含量) 및 흡수량(吸收量)이 증가(增加)하였으나 수량(收量)은 별영향(別影響)이 없었다. 2. 석회물질시용(石灰物質施用)으로 수도(水稻)의 납흡수억제효과(吸收抑制效果)가 인정(認定)되었다. 3. 물관리(管理)에서 수도(水稻)의 납흡수억제효과(吸收抑制效果)는 간단관수구(間斷灌水區)가 상시담수구(常時湛水區)보다 좋았다. 4. 토양중(土壤中) pb/Ca+Mg당량비(當量比)가 증가(增加)할수록 식물체중(植物體中) 납함량(含量)이 증가(增加)하였다. 5. 석회물질시용(石灰物質施用)에 따른 토양(土壤)의 pH는 소석회(消石灰)>규회석(硅灰石)>무시용(無施用)의 순(順)이었다. 6. 시험후(試驗後) 토양중(土壤中) $1N-NH_4$ OAC 가용성(可溶性) 납함량(含量)은 상시담수구(常時湛水區)가 간단관수구(間斷灌水區)보다 높았고 석회물질별(石灰物質別)로는 무시용(無施用)>규회석(硅灰石)>소석회(消石灰)의 순(順)이었다.

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폐기된 해조류를 이용한 납 이온의 흡착 특성 (Adsorption Features of Lead Ion on Waste Undaria pinnatifida)

  • 서명순;김동수
    • 자원리싸이클링
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    • 제13권4호
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    • pp.23-31
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    • 2004
  • 수산물 처리시 폐기물로 발생하는 Undaria pinnatifida 를 $Pb^{2+}$ 가 함유된 폐수의 흡착처리시 흡착제로 활용하는 방안을 검토하였다. 성분분석 결과, Undaria pinnatifida는 주로 탄화수소화합물로 구성되어 있었으며 비표면적이 상당히 높아 흡착제로서의 잠재적 활용도가 큰 것으로 파악되었다. Undaria pinnatifida 입자의 Electrokinetic Potential은 pH 8 부근에서 음의 최대값을 보였으며 전 pH 범위에 걸쳐 음으로 하전되어 양이온의 흡착에 적합한 것으로 검토되었다. $Pb^{2+}$는 실험조건에서 반응개시 수 분 이내에 대부분이 흡착되었으며 평형에 도달하는 시간은 약 30분 정도인 것으로 나타났다. 또한, Undaria pinnatifida 표면에 대한 $Pb^{ 2+}$의 흡착은 Freundlich Isotherm 을 따르는 것으로 관찰되었으며 발열반응의 특성을 확인하였다. 산에 의한 흡착제의 전처리는 흡착능을 향상시켰으나 염기로 전처리할 경우에는 오히려 흡착능이 저하되었다. Undaria pinnatifida 표면에 존재하는 작용기들과 $Pb^{ 2+}$ 와의 Organometallic Complex 형성이 $Pb^{ 2+ }$의 흡착에 주요하게 작용하는 것으로 파악되었으며, 경쟁적 흡착질의 존재, ionic Strength 의 변화, 그리고 착화합물제가 수중에 공존할 경우 $Pb ^{2+}$ /의 흡착성이 상당한 영향을 받는 것으로 관찰되었다.

Pb-free Status and Strategy of Semiconductor Business in Samsung Electronics

  • Jeong Se-Young
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2004년도 ISMP Pb-free solders and the PCB technologies related to Pb-free solders
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    • pp.79-92
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    • 2004
  • RoHS compliant products are now being mass-produced. Eco-product(Pb-free+RoHS compliant+Halogen-free) will be possible from 2005. Pb-free flip chip will be qualified by 2004. 4Q. Lead Finish: SnBi-Under mass production Pd PPF-Under small production Matte Sn-will be internally qualified by 2004. 4Q Development of Pb-free Solder Ball: Stable Supply, Cost Down.

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포토리소그래피와 도금을 사용한 셀레늄화 납 나노와이어 합성 (Synthesis of Lead Selenide Nanowires by Photolithography and Electrodeposition Process)

  • 송영섭;이주열;이규환;임재홍
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2014년도 추계학술대회 논문집
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    • pp.305-305
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    • 2014
  • 포토리소그래피와 도금 공정을 통해 PbSe 나노와이어를 합성하였다. PbSe은 광센서 및 열전 물질로 많이 알려져있다. 이러한 응용처에의 향상된 성능을 위해 본 연구에서는 PbSe 나노와이를 합성하였다. 합성에 사용된 방법인 포토리소그래피와 도금 공정은 반도체 산업 전반에 인프라가 잘 구축된 공정이며, 병렬 공정이다. 따라서 본 연구는 경제적이며 대량생산이 가능한 PbSe 나노와이어의 합성법을 제안한다.

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Synthesis of Trimetallic Au@Pb@Pt Core-shell Nanoparticles and their Electrocatalytic Activity toward Formic Acid and Methanol

  • Patra, Srikanta;Yang, Hae-Sik
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1485-1488
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    • 2009
  • A facile, seed-mediated preparation method of trimetallic Au@Pb@Pt core-shell nanoparticles is developed. Au nanoparticles are the template seeds onto which sequentially reduced Pb and Pt are deposited. The trimetallic core-shell structure is confirmed by UV-Vis spectroscopy, TEM and EDS analysis, and cyclic voltammetry. The trimetallic Au@Pb@Pt core-shell nanoparticles show high electrocatalytic activity for formic acid and methanol electrooxidation.

Spectrophotometer에 의한 금속의 최상정량법에 관한 연구 (제 2 보) Dithizone에 의한 Pb의 미량정량법 (Studies on the Micro-determination of Metals by Spetrophotometry (II) Micro-determination of pb by Dithizone Method)

  • 노일협
    • 약학회지
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    • 제5권1호
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    • pp.24-26
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    • 1960
  • Micro-determination of Lead by Dithizone Method was studied as follows: 1) Max. absorption wave length of Dithizone-pb complex in CC $l_{4}$ soln. is 510m.mu., 2) at the range of 5.gamma.-120.gamma. pb content, Bourguer-Beer's law hold good, 3) co-existence of F $e^{++}$ Z $n^{++}$, and C $u^{++}$ interfere.rfere.

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연(Pb)에 의한 광계 II 활성억제에 미치는 인산 및 ATP 전처리의 보호효과 (Protective Effects of Phosphate and ATP Pretreatment on Pb-Inhibiting Photosystem II Activity)

  • 성민웅
    • Journal of Plant Biology
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    • 제25권1호
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    • pp.21-36
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    • 1982
  • The activity of photosystem II in isolated chloroplast form the leaves of Sedum sarmentosum was measured. The photoreduction rate of DCPIP by photosystem II showed the circadian rhythm with a peak at near midday sample for a continuing fine day and at near afternoon between nidday and sunset sample for a continuing cloudy day in summer. The optimum light intensity of photoreduction by photosystem II in the chloroplast preparation was about 5~9$\times$$10^4$ lux. The saturated light intensity was over 9$\times$$10^1$lux. Photosystem II activity was inhibited by even the lowest concentration of lead. When Pi and ATP of the same concentration as Pb were added to the reaction mixture containing Tris buffer lacking of Pi prior to Pb incubation, photosystem II activity was protected from Pb-inhibiting effect by the pretreament of Pi and ATP. It was assumed that Pb inhibiiton was probably due to one, P-depriving by the precipitates of $Pb_3$ $($Pb_4$)_2$ in the reaction mixture and the other, partially Pb-combing with Pi groups of the active site of photosystem II.

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Pb의 흡착에 영향을 미치는 토양의 특성 (Soil Properties Affecting the Adsorption of Lead)

  • 박상원
    • 한국환경과학회지
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    • 제8권1호
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    • pp.69-74
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    • 1999
  • Soil properties which affect the retention of Pb(I) were investigated in the laboratory. It was determined, through selective removal, that organic matter and Fe-oxides are of lesser importance in influencing Pb retention than are soil clay minerals. The following trend : clays > organic matter > Fe-oxides represents the relative importance of each constituent in the adsorption of Pb by soils. The consistently greater Pb uptake by surface over subsurface samples was apparently due to differences in organic matter content, inasmuch as organic matter removal from both resulted in similar adsorption characteristics. All five soils stooled exhibited a pH-dependent trend of adsorption. The extent of Pb adsorption was least at low pH values(4~5), was maximum in the neutral pH range, and leveled off or diminished under more alkaline conditions. There was no strong correlation between Pb uptake and soil cation exchange capacity as routinely measured by the NH$_4$OAc method. A knowledge of clay mineralogy in conjunction with soil pH is suggested as being the most reliable guide to predicting Pb retention by soils.

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