• 한국농공학회논문집
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• 제57권4호
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• pp.31-38
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• 2015

This study aims to assess the effectiveness of limestone, zeolite, and crushed concrete as capping material to block the release of heavy metals (As, Cu, Cr, Ni, and Pb) and reduce the sediment oxygen demand. The efficiency of limestone, zeolite, and crushed concrete was evaluated in a reactor in which a 1-cm thick layer of capping materials was placed on the sediments collected from Inchon north harbor. Dissolved oxygen concentration and heavy metal concentration in seawater above the uncapped sediments and capping material were monitored for 17 days. The sediment oxygen demand was in the following increasing order: crushed concrete ($288.37mg/m^2{\cdot}d$) < zeolite ($428.96mg/m^2{\cdot}d$) < limestone ($904.53mg/m^2{\cdot}d$) < uncapped ($981.34mg/m^2{\cdot}d$). The capping materials could reduce the sediment oxygen demand by blocking the release of biochemical matters consuming dissolved oxygen in seawater. It was also shown that zeolite and crushed concrete could effectively block the release of Cu, Ni, and Pb but those were not effective for the interruption of As and Cr release from marine contaminated sediments.

• 한국물환경학회지
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• 제32권6호
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• pp.546-551
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• 2016

In this study, capping with recycled aggregate and natural zeolite in marine sediment was performed to investigate its inhibitory effect on pollutants released from sediment to seawater. An experiment was performed by capping with amendments for 60 days, and concentrations of organic matter (COD), nitrate, phosphate and metallic elements (Ni, Zn, Cu, Pb, Cd, As, and Cr) were measured. Two capping materials effectively suppressed pollutant release. Recycled aggregate showed better effectiveness for organic pollutant, nitrate and phosphate release. Meanwhile, natural zeolite was effective for metallic elements. As a result, recycled aggregate and natural zeolite can be considered as cost-effective/inexpensive capping material candidates. Also, the capping material can be selected according to the target pollutant.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.138-138
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• 2008

Ti capping layer를 이용하여 NiGe의 열적 안정성을 향상시키는 연구를 수행하였다. N-type Ge(100) 기판에 30nm 두께의 Ni과 30nm 두께의 Ti capping layer를 E-beam evaporator를 이용하여 증착하고 $300^{\circ}C$에서 $700^{\circ}C$ 까지 30초간 $N_2$ 분위기에서 급속 열처리하여 Ni-Germanide를 형성하였다. XRD의 결과로부터 Ti capping layer 유무에 상관없이, 전 온도 범위에 걸쳐 NiGe 상이 형성된 것을 관찰할 수 있었다. 급속 열처리 온도에 따른 면저항 값을 측정한 경우, $300^{\circ}C$에서 $600^{\circ}C$까지의 열처리 온도 범위에서는 모든 시편들이 비슷한 면저항 값을 보인 반면, 열처리 온도가 $700^{\circ}C$ 이상에서는 Ti capping layer가 있는 시편이 Ti capping layer가 없는 시편보다 낮은 면저항 값을 갖는 것을 확인할 수 있었다. 이는 고온 열처리 시 Ti capping layer에 있는 Ti가 기판 방향으로 확산하여 NiGe grain boundary에 segregation 되고 그로 인하여 NiGe의 grain boundary 움직임을 억제하여 agglomeration 현상을 효과적으로 방지하였기 때문에 나타난 현상으로 사료된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.154-154
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• 2009

Cr capping layer를 이용하여 Titanium germanide의 열적 안정성을 향상시키는 연구를 수행하였다. n-type Ge(100) 기판 위에 전자빔 증착기를 이용하여 30nm 두께의 Ti와 Cr capping layer를 증착하고 $400\;^{\circ}C$에서 $800\;^{\circ}C$까지 30초간 N2 분위기로 급속 열처리하여 Ti germanide를 형성하였다. XRD결과로부터 Cr capping layer의 유무에 관계 없이 Ti germanide가 형성된 것을 관찰할 수 있었다. Ge 기판 위에 CTLM 패턴을 형성하고 실험을 진행하여 Ti germanide의 I-V 측정 데이터를 통해 Ohmic 특성을 알아보았고, contact resistance, sheet resistance, specific contact resistance를 구하였다.

• Journal of Korean Vacuum Science & Technology
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• 제5권2호
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• pp.33-37
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• 2001

We measured x-ray magnetic circular dichroism of Co films on Pd(111) surface with and without Pd capping layer at the Co L$_2$,$_3$ edges. Perpendicular magnetization and orbital-moment enhancement are induced by the capping layer. The increase of perpendicular magnetic anisotropy induced by capping layer is considered to result from the increase of surface anisotropy due to the hybridization at the surface.

• 한국농공학회논문집
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• 제56권3호
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• pp.11-17
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• 2014

We investigated the applicability of steel slag as a capping material in order to minimize phosphorus(P) release into seawater. Steel slag is a byproduct from the iron and steel industries and the use of steel slag has some advantages in respect of both cost and environmental concern. P removal by steel slag were studied in a batch system with respect to changes in contact time and initial concentration. Kinetic adsorption data were described well by pseudo 2nd order model, indicating rate limiting step for P adsorption to steel slag is chemical sorption. Equilibrium adsorption data fitted well to Langmuir isotherm model which describes for single layer adsorption. The maximum P adsorption capacity of steel slag was 7.134 mg-P/L. Increasing the depth of steel slag produced a positive effect on interruption of P release. More than 3 cm of steel slag was effective for blocking P release and 5 cm of steel slag was recommended as the depth for capping of P contaminated marine sediments. Increasing P concentration and flow rate had a negative effect on P removal ratio. It was concluded that the steel slag has a potential capping material for blocking P release from marine sediments.

• 한국세라믹학회지
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• 제51권6호
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• pp.560-565
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• 2014

Alumina nano-asperites were grown on plate-like alumina particles of which the surface had been covered with a capping agent to control the asperite formation sites on the particles. Utilized alumina source for asperite was nano sized ${\gamma}$-alumina, which was prepared by calcination of $Al(OH)_3$ at $600^{\circ}C$; silica suspension was used as the capping agent. Plate like alumina particles were covered by silica suspension and continuously heat-treated to $900^{\circ}C$ with nano sized ${\gamma}$-alumina, as the source material, under molten-salt atmosphere. Asperite growing site were controlled by the degree of coating of the capping agent; 10-20 nanosize of ${\theta}$-alumina were formed on the particle surface. On the other hand, alumina particles without capping agent were observed to undergo only step-like crystal growth during heat-treatment.

• 한국세라믹학회지
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• 제38권9호
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• pp.782-786
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• 2001

Cobalt silicide has been employed to Embedded DRAM (Dynamic Random Access Memory) and Logic (EDL) as contact material to improve its speed. We have investigated the influences of Ti and TiN capping layers on cobalt-silicided Complementary Metal-Oxide-Semiconductor (CMOS) device characteristics. TiN capping layer is shown to be superior to Ti capping layer with respect to high thermal stability and the current driving capability of pMOSFETs. Secondary Ion Mass Spectrometry (SIMS) showed that the Ti capping layer could not prevent the out-diffusion of boron dopants. The resulting operating current of MOS devices with Ti capping layer was degraded by more than 10%, compared with those with TiN.

• Restorative Dentistry and Endodontics
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• 제43권4호
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• pp.36.1-36.12
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• 2018

Objectives: Direct pulp capping is a treatment for mechanically exposed pulp in which a biocompatible capping material is used to preserve pulpal vitality. Biocompatibility tests in animal studies have used a variety of experimental protocols, particularly with regard to the exposure site. In this study, pulp exposure on the occlusal and mesial surfaces of molar teeth was investigated in a rat model. Materials and Methods: A total of 58 maxillary first molars of Wistar rats were used. Forty molars were mechanically exposed and randomly assigned according to 3 factors: 1) the exposure site (occlusal or mesial), 2) the pulp-capping material (ProRoot White MTA or Bio-MA), and 3) 2 follow-up periods (1 day or 7 days) (n = 5 each). The pulp of 6 intact molars served as negative controls. The pulp of 12 molars was exposed without a capping material (n = 3 per exposure site for each period) and served as positive controls. Inflammatory cell infiltration and reparative dentin formation were histologically evaluated at 1 and 7 days using grading scores. Results: At 1 day, localized mild inflammation was detected in most teeth in all experimental groups. At 7 days, continuous/discontinuous calcified bridges were formed at exposure sites with no or few inflammatory cells. No significant differences in pulpal response according to the exposure site or calcium-silicate cement were observed. Conclusions: The location of the exposure site had no effect on rat pulpal healing. However, mesial exposures could be performed easily, with more consistent results. The pulpal responses were not significantly different between the 2 capping materials.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.268-269
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• 2005

YBCO 박막형 초전도체(coated conductor) 제조를 위해서는 여러 층의 완충층이 필요하다. 현재 일반적인 완충층의 구조는 seed layer로써 $Y_2O_3$, diffusion barrier로 YSZ, capping layer로 $CeO_2$가 사용되고 있다. 특히, capping layer로 $CeO_2$는 YBCO와 lattice mismatch가 매우 우수한 산화물로 이용되고 있다 본 연구에서는 $CeO_2$ capping layer가 증착 방법에 따라 그 위에 증착되어지는 초전도층의 특성에 어떤 영향을 미치는지 연구하였다. $CeO_2$를 thermal evaporation과 PLD (pulsed laser deposition) 증착 방법으로 증착 한 후 그 위에 PLD 방법으로 YBCO를 증착하여 coated conductor의 성능을 평가하였다.