• 한국재료학회지
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• 제10권2호
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• pp.160-165
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• 2000

Sputter Cu(1-4.5at.%Mg) alloy를 100mTorr이하의 산소압력에서 온도를 증가시키며 열처리하였을 때 표연과 계면에서 형성된 MgO의 확산방지막 특성을 살펴보았다 먼저, $Cu(Mg)/SiO_2/Si$ 구조의 샘플을 열처리했을 때 계면에서는 $2Mg+SiO_2{\rightarrow}2MgO+Si$의 화학반응에 의해 MgO가 형성되는데 이 MgO충에 의해 Cu가 $SiO_2$로 확산되는 것이 현저하게 감소하였다. TiN/Si 기판 위에서도 Cu(Mg)과 TiN 계면에 MgO가 형성되어 Cu(4.5at.%Mg)의 경우 $800^{\circ}C$까지 Cu와 Si의 확산을 방지할 수 있었다. 표면에 형성된 MgO위에 Si을 증착하여 $Si/MgO(150\;{\AA})/Cu(Mg)/SiO_2/Si$구조로 만든 후 열처리했을 때 $150\;{\AA}$의 MgO는 $700^{\circ}C$까지 Si과 Cu의 확산을 방지할 수 있었다. 표면에 형성된 MgO($150\;{\AA}$)의 누설전류특성은 break down 5V, 누설전류 $10^{-7}A/\textrm{cm}^2$의 값을 나타냈다. 또한 $Si_3N_4/MgO$ 이중구조에서는 매우 낮은 누설전류밀도를 나타냈으며 MgO에 의해 $Si_3N_4$ 증착시 안정적인 계면이 형성됨을 확인하였다.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• 마이크로전자및패키징학회지
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• 제31권2호
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• pp.78-84
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• 2024

이산화탄소 (CO₂)의 전기화학적 환원은 CO₂를 고부가가치 탄소화합물로 변환하는 효과적인 방법으로 주목받고 있다. 본 논문에서는 e-beam 증착법과 양극 산화법을 이용하여 전기화학적 CO₂ 환원용 g-C₃N₄가 도입된 다공성 Au(pAu) 전극을 합성하는 손쉬운 방법과 그 특성에 대해 보고한다. 제작된 pAu@g-C₃N₄ 전극 (@ -0.9 VRHE)은 pAu 전극대비 더 우수한 전기화학적 성능을 보였다. CO₂ 환원 성능을 확인해 보았을 때, 두 전극 모두 CO 생성물에 대해 100%의 패러데이 효율 (FE)을 기록하였으며, pAu@g-C₃N₄ 전극은 최대 9.94 mg/s의 CO 생산량을 나타내어 pAu 전극에 비해 최대 2.2배 많은 CO를 생산하였다. 본 연구는 CO₂ 배출로 인한 기후 변화에 대응하는 경제적이며 지속 가능한 방법을 제공할 뿐만 아니라, 전기화학적 CO₂ 환원용 전극 개발에 크게 기여할 것으로 예상된다.

• KSBB Journal
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• 제11권5호
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• pp.518-523
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• 1996

효소 purine nucleoside phosphoryrase(NP)하 고 xanthine oxidase(XOD) 두 효소를 하나로 고정화시켜 산소 전극으로부터 ATPase 활성 계측용 바 이오 센서를 개발했다. 개발된 ATPase센서를 이용 해서 Thunnus albacares(Yeliowfin tuna), Tetra~ t turus audax(Striped marlin), Prognichthys agoo (Japanese flyingfish) 그리고 Cyprinus carpio ( ( Carp) 등의 각 4종의 어근육 단백질중의 $K^+-, Ca^{2}+- 그리고 Mg^{2+}-$ATPase 활성을 측정하였고, 시료 1 개를 측정는데 3분의 시간을 필요로 하였다. $K^+-, Ca^{2}+-$ATPase 활성의 경우 본 연구에셔 개발한 센 셔를 이용한 측정 결과와 종래(비색측정)법으로 측 정한 결과와의 사이에서 좋은 상관치를 얻었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.202-203
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• 2006

In the AC PDP, the MgO film is used as electrode protective film. This film must provide excellent ion bombardment protection, high secondary electron emission, and should be high transparent to visible radiation. In this study, we investigated the relations between the crystal orientation and e-beam evaporation process parameters. The crystal orientation of the MgO layer depends on the conditions of deposition. The parameters are the thickness of the MgO film $1000{\AA}-6500{\AA}$, the deposition rate $200{\AA}/min{\sim}440{\AA}/min$, the temperature $150^{\circ}C{\sim}250^{\circ}C$, and the distance between crucible and substrate 11cm ${\sim}$ 14cm. The temperature of substrate and evaporation rate of source material, or deposition rate of the film, are definitely related to the crystal orientation of the MgO thin film. The crystal orientation can be changed by the distance between the target(MgO tablet) and the substrate. However, the crystal orientation is not much affected by the thickness of MgO thin film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.114-115
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• 2007

In this study, low temperature sintering property of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with sintering adds were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_3O_8$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_3O_3$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. In the case of $H_3BO_3$ addition, the bulk density and dielectric constant were decreased but quality factor was increased with amount of $H_3BO_3$ additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3+xwt%H_3BO_3$ ceramics were moved to positive direction. In another case, SnO addition, the bulk density and dielectric constant were increased but Quality factor was decreased with amount of SnO additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$+ywt%SnO ceramics were shifted to negative direction. The dielectric constant, quality factor and TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with $2wt%H_3BO_3$ and 2.5wt%SnO sintered at $830^{\circ}C$ for 1h, were 28.5, 39,570GHz, $+9.34ppm/^{\circ}C$ and 29.86, 35,80000z, $-0.58ppm/^{\circ}C$, respectively.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.12.1-12.1
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• 2007

• 한국환경과학회지
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• 제9권1호
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• pp.95-99
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• 2000

Laboratory experiments were performed to investigate the effects of various factors on the phosphorus removal by electrolysis with aluminium electrodes. The efficiency of phosphorus removal increases with increasing of voltage applied, surface area of electrodes and electrolyte concentration, and decreasing of electrode distance. The phosphorus removal was not affected by the connection number of an electric circuit. The amount of aluminium ion eluted from electrodes according to Faraday's law was 4.47 mg and the A/P mole ratio was 2.14 at the electric current value of 20 mA.

• Journal of Information Display
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• 제3권4호
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• pp.13-18
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• 2002

In general, the background light that is produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to an imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes are found to occur during the reset period. We also adopted the MgO coated phosphor layer to improve the address voltage margin that was reduced when the bias voltage in the modified ramp reset waveform was applied. As a result, the address voltage margin of 45 V which is the same level of the conventional method was ortained and the dark room contrast ratio was improved up to 7500 : 1.

• Carbon letters
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• 제4권2호
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• pp.64-68
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• 2003

A study on the electrosorption of uranium ions onto a porous activated carbon fiber (ACF) was performed to treat uraniumcontaining lagoon sludge. The result of the continuous flow-through cell electrosorption experiments showed that the applied negative potential increased the adsorption kinetics and capacity in comparison to the open-circuit potential (OCP) adsorption for uranium ions. Effective U(VI) removal is accomplished when a negative potential is applied to the activated carbon fiber (ACF) electrode. For a feed concentration of 100 mg/L, the concentration of U(VI) in the cell effluent is reduced to less than 1 mg/L. The selective removal of uranium ions from electrolyte was possible by the electrosorption process.