• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.47-53
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• 2000

The fluxless wetting properties of TSM-coated glass substrate were evaluated by the wetting balance method. We could estimate the wettability of the TSM with new parameters obtained from the wetting balance test for one side-coated specimen. It was more effective in wetting to use Cu as a wetting layer and Au as a protection layer than to use Au itself as a wetting layer. The SnSb solder showed better wettability than SnAg, SnBi, and SnIn solders. The contact angle of the one side-coated glass substrate to the Pb-free solders could be calculated from the farce balance equation by measuring the static force and the tilt angle.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.147-163
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• 2003

European Union bans the usage of Pb in electronics from July 1 st, 2006. The Near-eutectic Sn-Ag-Cu alloys are the leading candidate Pb-free solders (for SMT card assembly). .The microstructure of Sn-Ag-Cu alloys is discussed in terms of solidification, composition and cooling rate. Methods of controlling Ag3Sn plates are discussed. .Thermo-mechanical fatigue behaviors of Sn-Ag-Cu solder joints are reviewed. Tin pest, whisker growth, electromigration of Pb-free solders are discussed.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.159-164
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• 2021

Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.295-298
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• 2003

The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-$B_2O_3-V_2O_5$. DTA, XRD and SEM were used to study and characterize BaO-ZnO-$B_2O_3-V_2O_5$ glasses. PbO free paste developed at this paper has thermal expansion of $74{\times}10^{-7}/^{\circ}C$, DTA transformation point of $460^{\circ}C$, and firing condition of $560^{\circ}C$, 10min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.453-454
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• 2005

PDP에 사용되는 유전체, 격벽재, 봉착재 등의 glass들은 모두 PbO를 다량 함유하는 저융점 유리조성계로 되어있다. 최근 환경규제에 따라 Pb 대체 재료의 개발이 필요하게 되었으며, 그에 대한 많은 연구들이 진행되고 있다. 본 연구에서는 투명 유전체를 겨냥한 저융점 이면서 무해한 3성분계 Pb-free 유리를 제조하였다. 또한 SnO 계 유리와의 혼합 용융에 의한 영향을 고찰하였으며, 유리로서의 고유물성과 응용용도별 특성을 함께 고찰하였다.

• Journal of Pharmaceutical Investigation
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• v.27 no.2
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• pp.109-117
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• 1997

In order to elucidate the effect of phenobarbital (PB) on the nonlinear pharmacokinetic behavior of naproxen (NAP), we compared the dose dependent hepatic intrinsic clearance, biliary excretion and protein binding of NAP in control rats to those in the PB-pretreated rats which were intraperitoneally pretreated with PB sodium (75 mg/kg) once a day for four days. NAP was injected via femoral (1.5 mg/kg) and portal(0.25, 0.5, 1.5, 15 and 30 mg/kg) vein to the control and PB-pretreated rats, respectively. And also, we measured the plasma free fraction of NAP with the equilibrium dialysis method and the biliary excreted total amounts of NAP in both rats. Plasma free fraction of NAP was decreased in lower concentration than $150\;{\mu}g/ml$ of NAP due to PB pretreatment. In higher concentration, however, plasma free fraction was increased. These in vitro results suggest that the total protein concentration was increased but the total binding capacity of NAP to protein was decreased by PB-pretreatment. The total plasma clearance and the hepatic intrinsic clearance of NAP had similar values in both groups, respectively. And, both clearances of NAP were significantly increased by PB-pretreatment. Even though the plasma free fractions of NAP in both groups were constantly remained within the concentration range according to the increase of administration dose, the hepatic intrinsic clearances of NAP were significantly increased in both groups with the increased dose. And, the biliary excreted total amounts of NAP were significantly increased by PB-pretreatment at the lower dose, but decreased at the higher dose. These in vivo results suggest that NAP represents the uncommon nonlinear pharmacokinetic behavior that the hepatic intrinsic clearance was enhanced with the increased dose, and that PB enhances further the hepatic intrinsic clearance of NAP with the increased dose due to its enzyme induction effect.

• Proceedings of the KWS Conference
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• 1999.10a
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• pp.99-102
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• 1999

• Proceedings of the KWS Conference
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• 2000.04a
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• pp.178-180
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• 2000

• Proceedings of the KWS Conference
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• 1998.05a
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• pp.157-158
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• 1998

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.75.1-75
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• 2000