• 제목/요약/키워드: Microbalance

검색결과 186건 처리시간 0.019초

Corrosion of Silver by Outgassing from Rubber

  • Sakai, Jun'ichi;Omoda, Masataka;Ishikawa, Yuichi
    • Corrosion Science and Technology
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    • 제7권2호
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    • pp.130-133
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    • 2008
  • Corrosion of silver by outgassed sulfur species from rubber has been investigated by means of quartz crystal microbalance technique (QCM) and cathodic reduction technique. Silver specimens were placed together with a rubber of predefined quantity in an enclosed environment. Corrosion progressed linearly with time and silver sulfide was found as the corrosion product during all the tests. No significant dependence on RH was observed, while the corrosion rate increased as temperature rose. Furthermore the corrosion rate increased logarithmically with the quantity of the rubber placed in the exposure environment. It may be suggested that the corrosion rate of silver is determined by the amount of outgassed sulfur species which is a function of temperature and the quantity of rubber contained in the exposure environment.

QCM Study of β-Casein Adsorption on the Hydrophobic Surface: Effect of Ionic Strength and Cations

  • Lee, Myung-Hee;Park, Su-Kyung;Chung, Chin-Kap;Kim, Hack-Jin
    • Bulletin of the Korean Chemical Society
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    • 제25권7호
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    • pp.1031-1035
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    • 2004
  • The adsorption kinetics of ${\beta}$-casein on a hydrophobic surface has been studied by means of the quartz crystal microbalance (QCM). The self assembled monolayer of 1-octadecanethiol on a gold coated quartz crystal was used as a hydrophobic surface for adsorption. The adsorption kinetics was monitored in different solution conditions. Formation of monolayer is observed in most cases. At high concentration of protein, micelle formation which is interrupted by high ionic strength of solution is observed. Casein binding cations such as $Ca^{2+},\;Ba^{2+}\;and\;Al^{3+}$ increase the hydrophobicity of the protein and the multiple layer adsorption occurs. The strong and weak points of the QCM method in the study of protein adsorption are discussed.

공진점변화검출용 QCM 센싱플랫폼을 이용한 폭발물 특이적 바이오수용체 성능평가 (Performance Evaluation of Explosive Specific Bio-receptor Using QCM Sensing Platform for Resonance Frequency Shift Detection)

  • 임시형;정현진
    • 한국소음진동공학회논문집
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    • 제21권3호
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    • pp.280-284
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    • 2011
  • The mass change during the molecular interaction between explosive specific bio-receptors and target molecules has been measured using quartz crystal microbalance(QCM), which has a mass change detection limit up to ~ng/$cm^2$. The environmental effect on the molecular interaction has been evaluated. In the liquid phase molecular interaction experiments, the high selectivity of the bio-receptor to DNT compared with toluene has been shown and the sensitivity for various concentrations of DNT has been demonstrated.

LB막을 누적한 수정진동자의 임피던스 특성 (The Impedance Properties of Quartz Crystal Microbalance Coated with LB films)

  • 진철남;김경환;유승엽;박재철;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.171-174
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    • 1998
  • Quartz crystal in contact with viscoelastic medium is described directly in terms of the electrical equivalent circuit of the system. Stearic acid is used as viscoelastic medium and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. Impedance properties of quartz crystal coated with LB films which were investigated and the possibility of applying the technique to chemical sensing introduced.

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수정진동자 미량저울을 이용한 공기 중 먼지의 온라인 측정 (On-Line Measurement of Solid Particles in Air Using a Quartz Crystal Microbalance)

  • 최광재;김영한;장상목
    • 센서학회지
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    • 제8권4호
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    • pp.314-319
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    • 1999
  • 공기중의 먼지를 수정진동자를 이용한 미량저울을 써서 측정하는 실험을 수행하였다. 측정장치를 컴퓨터에 연결하여 여러 개의 센서를 활용함으로서 동시측정이 가능한 장치를 만들었다. 본 연구에서는 실험장치의 구체적인 사항을 자세히 설명하여 비슷한 장치를 이용한 다른 유사한 실험에 활용하는 데 도움을 주고자 하였다. 연구의 결과 본 측정시스템이 공기 중 먼지농도의 연속측정에 적합함을 알 수 있었다.

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Quartz crystal Microbalance(QCM)-based Immunosensor for the Determination of LDL(Low-Density Lipoprotein)

  • Kim, Sang-Hyun;Yoon, Hyun-Chul;Kwak, Joo-Won;Kim, Hak-sung
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1996년도 정기총회 및 학술발표회
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    • pp.44-44
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    • 1996
  • Immunoserisor for the determination of LDL(Low-Density Lipoprotein) was developed by using quartz crystal microbalance(QCM) system. LDL is known to be a good indicator for the diagnosis of atherosclerosis and hypercholesterolemia. The immunosensor consists of four parts; detection cell, oscillating circuit, oscilloscope, and frequency counter, and this was interfaced with personal computer for signal processing. (omitted)

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Al/Pd 박막의 수소 흡수 특성 (Hydrogen Absorption Characteristics of Al/Pd Film)

  • 조영신
    • 한국수소및신에너지학회논문집
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    • 제17권2호
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    • pp.234-240
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    • 2006
  • Al film(135.5 nm thick) with Pd film(39.6 nm thick) on the top of it was made by thermal evaporation method. Hydrogen absorption of Al/Pd film was measured by quartz crystal microbalance(QCM) method at room temperature. The sample was activated by hydrogen absorption and desorption cycling at room temperature. Hydrogen was introduced into the film by increasing hydrogen gas pressure step by step up to 640 torr at room temperature. Hydrogen concentration reached up to 25% at $5{\sim}10$ torr. But at high pressure the concentration decreased. This strange tendency was not understood yet. Further study is needed to find out the mechanism of hydrogen absorption in Al in Al/Pd film.

Optimization of Quartz Crystal Microbalance-Precipitation Sensor Measuring Acetylcholinesterase Activity

  • Kim, Nam-Soo;Park, In-Seon;Kim, Dong-Kyung
    • Journal of Microbiology and Biotechnology
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    • 제16권10호
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    • pp.1523-1528
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    • 2006
  • The optimization of a batch-type quartz crystal microbalance (QCM)-precipitation sensor measuring acetylcholinesterase (AChE) activity was conducted. To covalently bind AChE onto the gold electrode of a QCM surface, glutaraldehyde cross-linking to a cystamine self-assembled monolayer was tried at different cystamine concentrations. At the optimum conditions of the QCM-precipitation sensor, 0.1 M potassium phosphate buffer (pH 8.0), containing 0.01% Tween 80, was used as the reaction buffer, with the enzyme amount of 5 units for immobilization and the substrate concentration of 50 mg/ml. The current biosensor might find a future applicability to the sum parameter detection on organophosphorus and carbamate pesticides.

자기조립된 Viologen 단분자막의 모폴로지 관찰과 전하이동 특성 연구 (Study on Morphology Investigation and Electron-Transfer Property of Self-Assembled Viologen Monolayers)

  • 이동윤;박상현;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.395-396
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    • 2005
  • We fabricated self-assembled monolayers(SAMs) onto quartz crystal microbalance(QCM) using viologen, which has been widely used as electron acceptor and electron transfer mediator. We determined the time dependence to resonant frequency shift during self-assembly process and observed the morphology of self-assembled mono layers by STM and investigated the electrochemical behavior of SAMs by cyclic voltammetry. Electrochemical deposition of viologen was investigated using electrochemical quartz crystal microbalance(EQCM). The redox reactions of viologen were highly reversible and the EQCM has been employed to monitor the electrochemically induced adsorption of SAMs during the redox reactions.

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