• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.62-65
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• 2003

In this study, to confirm corrosion of reinforced concrete affected by carbonation, chloride ion diffusion, absorption ratio, air permeability, measured carbonation velocity coefficient, chloride ion diffusion coefficient, absorption coefficient, air permeability coefficient. Corrosion velocity under environment of complex deterioration. And than compared corrosion velocity with these coefficients. As the results of this study, the correlation coefficient between chloride ion diffusion coefficients and absorption coefficient was revealed that it is very high. As well, an increase in carbonation, chloride ion diffusion also increases corrosion velocity. It showed that corrosion velocity was affected by the carbonation, chloride ion diffusion, absorption ratio, air permeability. Generally, data on the development of these coefficient made with none, organic B, organic A, inorganic B, and inorganic A is shown. It showed that coating of surface prevent steel bar from deteriorating.

• 대한기계학회논문집
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• 제18권9호
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• pp.2486-2493
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• 1994

Transient heat transfer characteristics in th radiant heating panel with heat diffusion fin were predicted by numerical analysis. Thermal behaviors of panel, such as temperature distributions in panel and convective and radiative heat fluxes in panel surface with advance of time, were obtained for several important parameters. The performance and thermal comfort of heating panel were studied and compared for various design conditions, such as pipe pitch, area ratio and thermal conductivity of optimal design of the new heating panels with heat diffusion fin. It was concluded that the efficient area ratio of heat diffusion fin is about 0.5, and the greater the thermal conductivity of fin is, the better the performance of panel is.

• 한국구조물진단유지관리공학회 논문집
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• 제21권2호
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• pp.46-52
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• 2017

염해에 노출된 콘크리트 구조물의 내구수명 평가는 매우 중요하므로 최근들어 결정론적 및 확률론적 방법을 통하여 내구수명을 평가하는 시도가 이루어지고 있다. Fick's 2nd 법칙에 근거한 내구수명 평가방법은 표면 염화물량과 확산계수의 시간의존성을 고려하여 합리적인 설계를 수행하고 있으나, 확률론적 방법에서는 이러한 영향이 고려되지 않고 있다. 본 논문에서는 시간에 따라 증가하는 표면염화물량을 유효 표면염화물량으로 고려한 뒤 시간의존성 확산계수를 고려하여 내구적 파괴확률을 도출할 수 있는 해석기법을 제안하였다. 표면염화물에 도달하는 기간을 10~30년으로, 표면염화물량을 $5.0{\sim}10.0kg/m^3$으로 변화시키면서 내구적 파괴확률을 평가하고 내구수명의 변화를 분석하였다. 제안된 기법은 결정론적 내구수명 평가방법의 해석조건을 동일하게 적용시키면서 설계인자의 확률 변동성을 고려할 수 있으므로 과다한 설계를 방지함으로서 합리적인 설계기법으로 적용할 수 있다.

• 한국표면공학회지
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• 제49권3호
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• pp.286-300
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• 2016

Pd-Ag alloy membranes have attracted a great deal of attention for their use in hydrogen purification and separation due to their high theoretical permeability, infinite selectivity and chemical compatibility with hydro-carbon containing gas streams. For commercial application, Pd-based membranes for hydrogen purification and separation need not only a high perm-selectivity but also a stable long-term durability. However, it has been difficult to fabricate thin, dense Pd-Ag alloy membranes on a porous stainless steel metal support with surface pores free and a stable diffusion barrier for preventing metallic diffusion from the porous stainless steel support. In this study, thin Pd-Ag alloy membranes were prepared by advanced Pd/Ag/Pd/Ag/Pd multi-layer sputter deposition on the modified porous stainless steel support using rough polishing/$ZrO_2$ powder filling and micro-polishing surface treatment, and following Ag up-filling heat treatment. Because the modified Pd-Ag alloy membranes using rough polishing/$ZrO_2$ powder filling method demonstrate high hydrogen permeability as well as diffusion barrier efficiency, it leads to the performance improvement in hydrogen perm-selectivity. Our membranes, therefore, are expected to be applicable to industrial fields for hydrogen purification and separation owing to enhanced functionality, durability and metal support/Pd alloy film integration.

• 한국표면공학회지
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• 제47권5호
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• pp.227-232
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• 2014

In this study, we propose the application of doping process technology for atmospheric pressure plasma. The plasma treatment means the wafer is warmed via resistance heating from current paths. These paths are induced by the surface charge density in the presence of illuminating Argon atmospheric plasmas. Furthermore, it is investigated on the high-concentration doping to a selective partial region in P type solar cell wafer. It is identified that diffusion of impurities is related to the wafer temperature. For the fixed plasma treatment time, plasma currents were set with 40, 70, 120 mA. For the processing time, IR(Infra-Red) images are analyzed via a camera dependent on the temperature of the P type wafer. Phosphorus concentrations are also analyzed through SIMS profiles from doped wafer. According to the analysis for doping process, as applied plasma currents increase, so the doping depth becomes deeper. As the junction depth is deeper, so the surface resistance is to be lowered. In addition, the surface charge density has a tendency inversely proportional to the initial phosphorus concentration. Overall, when the plasma current increases, then it becomes higher temperatures in wafer. It is shown that the diffusion of the impurity is critically dependent on the temperature of wafers.

• 한국건설순환자원학회논문집
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• 제8권1호
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• pp.143-151
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• 2020

최근 자기치유 콘크리트의 연구가 활발히 진행되고 있으며, 구조물의 유지관리에 활용하기 위한 다양한 방법이 시도되고 있다. 하지만 자기치유 콘크리트의 기술적인 발전과는 달리, 성능을 평가하기 위한 방법은 불충분한 실정이다. 비록 표면관찰과 투수실험을 통해서 균열의 치유를 관찰하는 방법이 널리 실행되고 있지만, 현미경 관찰을 통한 표면관찰 방법은 국부적인 지점의 관찰은 전체적인 성능을 평가하기에는 불충분할 수 있으며, 투수실험의 경우에는 물질용출 및 점성으로 인한 손실을 고려해야 한다. 상기의 두 실험방법의 단점을 보완한 기체확산실험이 개발되었지만, 실제 치유가 발생한 시편을 대상으로의 검증은 이루어지지 않았다. 따라서 본 연구에서는 치유가 발생한 모르타르 시편에 대해 기체확산실험을 진행하였고, 기체확산실험에 의한 자기치유 평가의 적정성을 검증하였다.

• 한국재료학회지
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• 제28권5호
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• pp.286-294
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• 2018

Hot-press forming(HPF) steel can be applied successfully to auto parts because of its superior mechanical properties. However, its resistances to aqueous corrosion and the subsequent hydrogen embrittlement(HE) decrease significantly when the steel is exposed to corrosive environments. Considering that the resistances are greatly dependent on the properties of coating materials formed on the steel surface, the characteristics of the corrosion and hydrogen diffusion behaviors regarding the types of coating material should be clearly understood. Electrochemical polarization and impedance measurements reveal a higher corrosion potential and polarization resistance and a lower corrosion current of the Al-coating compared with Zn-coating. Furthermore, it was expected that the diffusion kinetics of the hydrogen atoms would be much slower in the Al-coating, and this would be due mainly to the much lower diffusion coefficient of hydrogen in the Al-coating with a face-centered cubic structure. The superior surface inhibiting effect of the Al-coating, however, is degraded by the formation of local cracks in the coated layer under severe stress conditions, and therefore further study will be necessary to gain a clearer understanding of the effect of cracks formed on the coated layer on the subsequent corrosion and hydrogen diffusion behaviors.

• 한국표면공학회지
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• 제48권6호
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• pp.322-328
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• 2015

We investigated the diffusion behaviors, electrical properties, microstructures, and composition of In-Ga-Zn-O (IGZO) oxide thin films deposited by radio frequency reactive magnetron sputtering with increasing annealing temperatures. The samples were deposited at room temperature and then annealed at 300, 400, 500, 600 and $700^{\circ}C$ in air ambient for 2 h. According to the results of time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy, no diffusion of In, Ga, and Zn components were observed at 300, 400, 500, $600^{\circ}C$, but there was a diffusion at $700^{\circ}C$. However, for the sample annealed at $700^{\circ}C$, considerable diffusion occurred. Especially, the concentration of In and Ga components were similar at the IGZO thin film but were decreased near the interface between the IGZO and glass substrate, while the concentration of Zn was decreased at the IGZO thin film and some Zn were partially diffused into the glass substrate. The high-resolution transmission electron microscopy results showed that a phase change at the interface between IGZO film and glass substrate began to occur at $500^{\circ}C$ and an unidentified crystalline phase was observed at the interface between IGZO film and glass substrate due to a rapid change in composition of In, Ga and Zn at $700^{\circ}C$. The best values of electron mobility of $15.5cm^2/V{\cdot}s$ and resistivity of $0.21{\Omega}cm$ were obtained from the sample annealed at $600^{\circ}C$.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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• pp.50-50
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• 2011

• 대한전자공학회논문지
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• 제22권2호
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• pp.97-105
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• 1985

PECVD 방법으로 만들어진 도핑한 박막에서 실리콘으로의 인이나 붕소의 확산 특성이 연구되었다. CVD PSC 박막도 역시 만들어면 PECVD PSG에 있는 인의 확산특성과 나란히 비교되었다. 인의 부산은 N2와 O2 분위기 및 1000℃, 1,050℃, 1,100℃의 온도에서 수행되었다. 붕소의 확산 변수들은 B2H2유량 및 박막형성 온도를 달리하여 만들어진 박막에 관하여 고찰되었다. 실리콘으로의 주입물 확산 계수와 확산 Profile이 측정된 혹산 깊이 및 불순물 표면 농도를 써서 Barry의 모델을 적용하여 계산되었다.