• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2001년도 춘계학술발표회요약집
• /
• pp.547.2-547
• /
• 2001

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2004년도 춘계총회 및 학술발표회
• /
• pp.32-32
• /
• 2004

• Corrosion Science and Technology
• /
• 제3권4호
• /
• pp.131-139
• /
• 2004

Effects of PbO on the repassivation kinetics and characteristics of passive film of Alloy 690 were examined to elucidate the influences of PbO on the SCC resistance of that alloy. The repassivation kinetics of the alloy was analyzed in terms of the current density flowing from the scratch, i(t), as a function of the charge density that has flowed from the scratch, q(t). Repassivation on the scratched surface of the alloy occurred in two kinetically different processes; passive film initially nucleated and grew according to the place exchange model in which log i(t) is linearly proportional to q(t), and then grew according to the high field ion conduction model in which log i(t) is linearly proportional to 1/q(t) with a slope of cBV. The cBV is found to be a parameter representing repassivation rate and hence SCC susceptibility of the alloy. The lower the value of cBV, the faster the repassivation rate and the higher the SCC resistance of an alloy. Addition of PbO to pH 4 and 10 solutions increased the value of cBV of alloy 690, reflecting slower repassivation rate than without PbO. The change in the value of cBV was grater in pH 10 than in pH 4. The increase in SCC susceptibility of alloy 690 with the addition of PbO to solution was presumably due to the Cr-depletion in the outer parts of passive film of the alloy with an incorporation of Pb compounds in the film, which was revealed by Mott-Schottky, AES and XPS analyses.

• 한국식품과학회지
• /
• 제37권6호
• /
• pp.933-938
• /
• 2005

감자절편의 포장재 및 포장방법에 따른 저장 중 품질 변화를 조사하였다. 감자절편을 무포장, polyethylene film(PE), polypropylene film(PP), anti-fogging film(AF), perforated film(PF)을 이용한 일반 MA포장과 Nylon/PP film을 이용한 가스치환포장(MA1, MA2) 및 진공(VF)포장을 한 후 $5^{\circ}C$에 저장하면서 중량감소, 표면색, 비타민 C 함량 및 관능적 품질변화를 조사하였다. 저장 중 감자의 호흡률은 절단 한 것이 절단하지 않은 것에 비하여 2.11배 높았다. 포장 내 기체조성은 밀봉 7일 이후부터 $O_2$농도는 1-2% 내외로 안정되었고, $CO_2$농도는 포장재질에 따라서 4-14% 범위를 유지하였다. 중량감소와 갈변발생은 PP 포장구와 MA2 포장구에서 적었고, 경도는 포장구간에 유의적인 차이를 나타내지 않으며, 비타민 C 함량은 AF포장구에서 가장 적은 변화를 나타내었다. 관능적 품질은 MA2 포장구가 저장 10일까지 가장 우수하였으며, 그 다음에 PP포장구 및 AF포장구순으로 우수하였다.

• 대한화학회지
• /
• 제53권4호
• /
• pp.466-470
• /
• 2009

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1996년도 추계학술대회 논문집
• /
• pp.389-392
• /
• 1996

The recent development of high temperature superconducting epitaxial thin film offer great potential for planar passive microwave application such as ring resonator, filters, transmission lines, and antennas. This paper describes the fundamental properties of Microstrip Band-Pass Filter using HTS Thin Film and its application to microwave devices. In order to fabricate HTS microstrip multiple filters, We have grown laser ablated HTS thin films, patterned by photolithographic process and wet etching processes intro HTS microwave devices.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
• /
• pp.861-863
• /
• 2003

In this work, the preparations and characteristics of capacitors and inductors for RF IC as a integrated devices are investigated. These kinds of capacitors and inductors can be applicable to the passive components utilized in voltage controlled oscillator(VCO), low noise amplifier(LAN), mixer and synthesizer for mobile telecommunication of radio frequency band(900 MHz to 2.2GHz), and in a library of monolithic microwave integrated circuit(MMIC). The results show that these inductors and capacitors array for RF IC may be applicable to the RF IC passive components for mobile telecommunication.

• 동력기계공학회지
• /
• 제20권3호
• /
• pp.17-21
• /
• 2016

The corrosion behavior of aluminum alloys in the $H_2SO_4$ solution was investigated based on potentiodynamic techniques. Electrochemical properties, such as corrosion potential($E_c$), passive potential($E_p$), corrosion current density($I_c$), corrosion rate(mpy), of Al-Mg-Si, Al-Cu-Si and Al-Si alloys were characterized at room temperature. Passive aluminum oxide film, which including $Al_2(SO_4)_3$ and $3Al_2O_34SO_38H_2O$, were uniformly formed on the surface via the reaction of Al with $SO{_3}^{2-}$ or $SO{_4}^{2-}$ ions in the $H_2SO_4$ solution and the dependence of the corrosion behavior on the alloying element was discussed. The selective leaching of alloy element increased with increasing Cu content in the aluminum alloys.

• Corrosion Science and Technology
• /
• 제17권6호
• /
• pp.310-316
• /
• 2018

The effect of passive film on corrosion of metals and alloys in a static corrosive environment has been studied by many researchers and is well known, however few studies have been conducted on the electrochemical measurement of metals and alloys during cavitation corrosion conditions, and there are no test standards for electrochemical measurements 'During cavitation' conditions. This study used commercially additive manufactured(AM) pure titanium in tests of anodic polarization, corrosion potential measurements, AC impedance measurements, and repassivation. Tests were performed in 3.5% NaCl solution under three conditions, 'No cavitation', 'After cavitation', and 'During cavitation' condition. When cavitation corrosion occurred, the passive current density was greatly increased, the corrosion potential largely lowered, and the passive film revealed a small polarization resistance. The current fluctuation by the passivation and repassivation phenomena was measured first, and this behavior was repeatedly generated at a very high speed. The electrochemical corrosion mechanism that occurred during cavitation corrosion was based on result of the electrochemical properties 'No cavitation', 'After cavitation', and 'During cavitation' conditions.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제4C권2호
• /
• pp.73-76
• /
• 2004

0-3 PbTiO$_3$/P(VDF/TrFE) nanocomposite thin films for passive pyroelectric infrared sensors were fabricated by a two-step spin coating technique. 65wt% VDF and 35 wt% TrFE was formed into a P(VDF/TrFE) powder. Nano size PbTiO$_3$ powder was used. 0-3 connectivity of PbTiO$_3$/P(VDF/TrFE) composite film was successfully achieved and observed using SEM photography. The dielectric constant and pyroelectric coefficient were measured and compared with P(VDF/TrFE). A very low dielectric constant (13.48 at 1KHz and sufficiently high pyroelectric coefficient (3.101 nC/$\textrm{cm}^2$ㆍk at 5$0^{\circ}C$) were measured. This nanocomposite can be used for a new pyroelectric infrared sensor to achieve better performance.