• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.254-259
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• 2005

In this study, measurement of thermal conductivity of multilayer thin dielectric film has been conducted via differential 3$\omega$ method. Also, verification of differential 3$\omega$ method has been accomplished with various proposed criteria. The target film for measurement is 300 nm silicon dioxide and this thin film is covered with various thicknesses of upper protective layer. The upper protective layer is inserted between the target film and the heater line for purpose of electrical insulator or anti-oxidation barrier since the target film may be a good electrical conductor or a well-oxidizing material. However, the verification of differential 3$\omega$ method has not been conducted. Thus we have shown that the measurement of thermal conductivity of thin films with upper protective layer via differential 3$\omega$ method is verified to be reliable as long as the proposed preconditions are satisfied. Experimental results show that the experimental errors tend to increase with aspect ratio between upper protective layer thickness and width of the heater line due to heat spreading effect.

• 정보저장시스템학회논문집
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• 제2권1호
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• pp.85-90
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• 2006

In this study, measurement of thermal conductivity of multilayer thin dielectric film has been conducted via differential $3\omega$ method. Also, verification of differential $3\omega$ method has been accomplished with various proposed criteria. The target film for the measurement is 300 nm thick silicon dioxide which is covered with upper protective layer of various thicknesses. The upper protective layer is inserted between the target film and the heater line for purpose of electrical insulator or anti-oxidation barrier since the target film may be a good electrical conductor or a well-oxidizing material. Since the verification of differential $3\omega$ method has not been conducted yet, we have shown that the measurement of thermal conductivity of thin films with upper protective layer via differential $3\omega$ method is verified to be reliable as long as the proposed preconditions of the samples are satisfied. Experimental results show that the experimental errors tend to increase with aspect ratio between thickness of the upper protective layer and width of the heater line due to heat spreading effect.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.419-419
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• 2010

최근 AC-PDP의 효율향상을 위해 MgO Protective Layer 위에 별도의 기능막(Functional Layer)을 적용하고 있으며 기능막의 재료로는 MgO 나노 입자를 사용하고 있다. 그러나 장시간 구동시 AC-PDP Panel 내에서 Plasma 방전에 의하여 MgO Protective Layer와 기능막이 방전 공간에 형성 된 이온에 의해 Sputtering 또는 재 증착 될 수 있다. 본 실험에서는 기능막이 적용된 AC-PDP Test Panel을 제작하여 장시간 구동 후 MgO Protective Layer와 기능막인 MgO 나노 입자의 재형성된 형태를 주사 전자 현미경(Scanning Electron Microscope)을 통해 Surface Profile 및 구조의 변화를 분석하고, 또한 음극선 분광 분석(Cathodoluminascence)을 통하여 방전 영역과 비방전 영역의 delay time, 방전전압 및 효율 등의 전기 광학적 특성과의 관계를 분석하고자 한다.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.162-173
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• 2023

Aqueous zinc-ion batteries are considered as promising alternatives to lithium-ion batteries for energy storage owing to their safety and cost efficiency. However, their lifespan is limited by the irreversibility of Zn anodes because of Zn dendrite growth and side reactions such as the hydrogen evolution reaction and corrosion during cycling. Herein, we present a strategy to restrict direct contact between the Zn anode and aqueous electrolyte by fabricating a protective layer on the surface of Zn foil via phosphidation method. The Zn₃(PO₄)₂ protective layer effectively suppresses Zn dendrite growth and side reactions in aqueous electrolytes. The electrochemical properties of the Zn₃(PO₄)₂@Zn anode, such as the overpotential, linear polarization resistance, and hydrogen generation reaction, indicate that the protective layer can suppress interfacial corrosion and improve the electrochemical stability compared to that of bare Zn by preventing direct contact between the electrolyte and the active sites of Zn. Remarkably, MnO₂ Zn₃(PO₄)₂@Zn exhibited enhanced reversibility owing to the formation a stable porous layer, which effectively inhibited vertical dendrite growth by inducing the uniform plating of Zn²⁺ ions underneath the formed layer.

• Geomechanics and Engineering
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• 제28권3호
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• pp.209-224
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• 2022

In this study, the numerical analysis model of π-beam explosion is established to compare and analyze the failure modes of the π-beam under the action of explosive loads, thus verifying the accuracy of the numerical model. Then, based on the numerical analysis of different protection forms of π beams under explosive loads, the peak pressure of π beam under different protection conditions, the law of structural energy consumption, the damage pattern of the π beam after protection, and the protection efficiency of different protective layers was studied. The testing results indicate that the pressure peak of π beam is relatively small under the combined protection of steel plate and aluminum foam, and the peak value of pressure decays quickly along the beam longitudinal. Besides, as the longitudinal distance increases, the pressure peak attenuates most heavily on the roof's explosion-facing surface. Meanwhile, the combined protective layer has a strong energy consumption capacity, the energy consumed accounts for 90% of the three parts of the π beam (concrete, steel, and protective layer). The damaged area of π beam is relatively small under the combined protection of steel plate and aluminum foam. We also calculate the protection efficiency of π beams under different protection conditions using the maximum spalling area of concrete. The results show that the protective efficiency of the combined protective layer is 45%, demonstrating a relatively good protective ability.

• Corrosion Science and Technology
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• 제7권2호
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• pp.119-124
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• 2008

Steel is generally not corrosion resistant to water with formation of non protective rusts on its surface. Rusts are composed of iron oxides such as $Fe_3O_4$, $\alpha-$, $\beta-$, $\gamma-$and ${\delta}-FeOOH$. However, steel, particularly weathering steel containing small amounts of Cu, Ni and Cr etc., shows good corrosion resistance against rural, industrial or marine environment. Its corrosion rate is exceedingly small as compared with that of carbon steel. According to the exposure test results undertaken in outdoor environments, the atmospheric corrosion rate for weathering steel is only 1 mm for a century. Atmospheric corrosion for steels proceeds under alternate dry and wet conditions. Dry condition is encountered on steel surface on fine or cloudy days, and wet condition is on rainy or snowy days. The reason why weathering steel shows superior atmospheric corrosion resistance is due to formation of corrosion protective rusts on its surface under very thin water layer. The protective rusts are usually composed of two layer rusts; the upper layer is ${\gamma}-FeOOH$ termed as lepidocrocite, and inner layer is nano-particle ${\alpha}-FeOOH$ termed as goethite. This paper is aimed at elucidating the atmospheric corrosion mechanism for steel in comparison with corrosion in bulky water environment by use of empirical data.The summary is as follows: 1. No corrosion protective rusts are formed on steel in bulky water. 2. Atmospheric corrosion for steel is the corrosion under wetting and drying conditions. Corrosion and passivation occur alternately on steel surface. Steel, particularly weathering steel with small amounts of alloying elements such as Cu, Ni and Cr etc. enhances forming corrosion protective rusts by passivation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 토목섬유기술위원회 학술세미나 논문집
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• pp.55-65
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• 2001

Geotextiles are usually constructed as a protective layer of geomembranes in liner systems for the solid waste landfill. A protective layer and geomembrane are susceptible to mechanical damage by coarse grains in the overlying drainage layer. In this study, therefore, the strain behavior of geotextile protective layers was investigated using three different types of devices for developing punctiform loads. The results of the study showed that the rates of strain was different depend upon device types for functiform loads. Also, It was found that the increases in strain was approximately linear in range 20 to 6$0^{\circ}C$ , and pp-filament non-woven geotextiles yielded a better efficiency than pp-staple fiber non-woven geotextiles.

• 한국화재소방학회논문지
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• 제32권1호
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• pp.81-88
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• 2018

공기와 초경량 소재인 에어로젤을 이용하여 소방용 특수방화복의 무게를 경량화하고자 하였다. 3겹(겉감, 중간층, 안감)으로 구성된 특수방화복을 경량화하기 위해서는 총무게에서 가장 큰 비중을 차지하는 안감을 신소재로 대체하는 것이 가장 효과적이었다. 열보호 성능시험은 대류 열원(ASTM D 4108), 복사 열원(KS K ISO 6942) 및 대류와 복사 혼합 열원(KS K ISO 17492)에 대해 수행하였다. 안감의 펠트를 공기층으로 대체하였을 경우 공기층이 최소 3 mm 이상일 때 열보호 성능이 KFI와 ISO 기준을 충족하였다. 그러나 공기층의 두께가 10 mm까지 늘어나도 열보호 성능이 기존 제품의 성능에 미치지 못했다. 안감의 펠트를 에어로젤로 대체하였을 경우 에어로젤의 두께가 2 mm일 때 TPP (ASTM D 4108) 값이 KFI 기준을 충족하였으며, 에어로젤의 두께가 3 mm일 때는 TPP 값이 기존 특수방화복보다 약 140% 향상되었다. 에어로젤을 사용할 경우 특수방화복의 경량화 뿐만 아니라 열보호 성능까지 향상됨을 확인하였다. 그러나 에어로젤은 부서지기 쉬운 성질이 있어서 특수방화복을 구성하는 층 사이에 일정한 두께로 고정시키는 방법이 향후 고려되어야 한다.

• 한국세라믹학회지
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• 제46권3호
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• pp.313-316
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• 2009

A zinc borosilicate glass having a low softening temperature of $490^{\circ}C$ has been investigated as a protective layer for Ag patterns against chemical reactions with a $I^-/I_3^-$ electrolyte in dye-sensitized solar cells (DSSCs). A thick glass layer was prepared by the typical screen printing and firing processes to obtain a final thickness of ${\sim}5{\mu}m$. The chemical leaching performance of the glass layer in the electrolyte revealed that the reactive Ag pattern can be significantly protected by utilizing the low softening protective layer. The electrical resistance of the FTO-coated glass substrate was effectively maintained at a low value of ${\sim}27{\Omega}$ as long as the glass layer was well densified at a sufficiently high temperature of ${\sim}520^{\circ}C$. The transmittance of the layer was near 60%, depending on the firing temperature of the glass layer.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.26.2-26.2
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• 2005