• 대한화학회지
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• 제37권8호
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• pp.735-743
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• 1993

Cofacial bis-cobalt tetraphenylporphyrin(Co-TPP) 유도체 화합물들이 수식된 유리질 탄소 전극과 carbon microelectrode을 작업 전극으로 사용하여 여러가지 pH 용액에서 순환 전압전류법 및 시간 전류법에 의해 산소의 환원반응을 조사하였다. 산성용액에서 monomer인 cobalt tetraphenylporphyrin 화합물이 수식된 전극에서 산소의 환원반응경로는 중간 생성물인 H$_2$O$_2$로 가는 2전자 반응으로, dimer인 cofacial bis-cobalt tetraphenylporphyrin 유도체 화합물들이 수식된 전극에서는 최종 생성물인 H$_2$O로 가는 4전자 반응으로 진행되었다. 이와 같은 산소의 환원반응은 전체적으로 비가역적이며 확산지배적인 반응으로 주어졌다. pH 변화에 따른 산소의 환원전위는 pH 13에서 pH 4 까지는 직선관계가 성립하였으나 강한 산성용액에서는 이들 관계가 성립하지 않았다. 산성용액에서 산소의 환원전위는 알몸 유리질 탄소전극에서 보다 monomer Co-TPP 화합물이 수식된 유리질 탄소전극에서는 400 mV만큼, dimer Co-TPP 화합물이 수식된 전극에서는 750 mV 만큼 더 양전위 방향으로 이동되었다.

• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.92-100
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• 2021

In this study, the use of waste food grade aluminium foil and mild steel as a sacrificial electrode in an electrocoagulation system was developed to remove reactive red 111 from wastewater. The effect of different parameters like pH, current density, electrode material, and different electrode configurations was investigated. Optimum operating conditions for maximum COD removal were determined as, 6 mA/㎠ current density and 30 min at 5 pH for aluminium foil and 7 pH for mild steel. Maximum COD reduction obtained at optimum conditions using monopolar 4 electrodes, monopolar 2 electrodes and bipolar electrode configuration were 96.5%, 89.3%, and 90.2% for Mild steel as a sacrificial electrode and 92.1%, 84.2%, and 88.6% for aluminium foil as a sacrificial electrode. The consumption of electrode and energy for both the electrodes of different configurations were calculated and compared. Using batch experimental data, a continuous-flow reactor was developed. Sludge analysis using Fourier Transform Infra-Red Spectroscopy (FTIR) analysis was done. Different adsorption kinetic models and isotherms were developed and it was found that pseudo second-order model and Langmuir isotherm fit best with the experimental data obtained.

• 전기학회논문지
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• 제65권10호
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• pp.1786-1791
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• 2016

The damage has occurred inside the semiconductor pattern When using conventional wet station for semiconductor. It was used for electrolytic ion water generator in order to prevent damage to the semiconductor pattern. It was designed and developed a flow path electrode and the mesh electrode to check the efficiency of the electrode. And It confirmed the expected results through the simulation of the flow path. and ORP were measured in accordance with the current and voltage of mesh electrode and flow paht electrodes. Flow path electrode 22A is 3V, up to pH 9.8, the value of ORP-558mV was measured and the mesh electrode was measured up to pH 9.8, ORP -350mV.

• 한국환경과학회지
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• 제17권1호
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• pp.37-44
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• 2008

The electro-chemical decolorization of Rhodamine B (RhB) in water has been carried out by electro Fenton-like process. The effect of distance, material and shape of electrode, NaCl concentration, current, electric power, $H_2O_2$ and pH have been studied. The results obtained that decrease of RhB concentration of Fe(+)-Fe(-) electrode system was higher than that of other electrode system. The decrease of RhB concentration was not affected electrode distance and shape. Decolorization of electro Fenton-like reaction, which was added $H_2O_2$ onto the electrolysis using electrode was higher than electrolysis. Addition of NaCl decreased the electric consumption. The lower pH is, the faster initial reaction rate and reaction termination time observed.

• 한국해양공학회지
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• 제19권2호
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• pp.53-59
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• 2005

The effect of pH on the corrosion characteristics in the dissimilar friction welded zone of IN713LC-SCM440 in the loaded torsional stress was studied. The corrosion experiment was performed for 120 hours on the specimens with five steps of pH. The surface corrosion pattern of the SCM440 area showed global corrosion and narrow pitting, which was caused by galvanic corrosion between friction welded IN713LC and SCM440, but corrosion did not proceeded from the IN713LC area. The average relative electrode potential gradually tends to decrease with the elapse of the immersion time in the acidity area. The average corrosion current also gradually tend to decrease The corrosion rate showed a larger value when the average relative electrode potential was higher and the average relative current was lower. The corrosion rate showed a larger value when the average relative electrode potential was higher in the acidity area, and it showed large when the average relative electrode potential was lower in the alkalinity area.

• 한국식품영양과학회지
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• 제35권4호
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• pp.507-509
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• 2006

미량확산법에 의한 휘발성 염기질소 분석에서 고체소자센서가 부착된 마이크로 pH 전극을 사용하여 적정 과정을 자동화하기 위하여 자동적정시스템을 구성하고 자동적정 프로그램을 작성하였다. 자동적정시스템으로 돈육시료의 휘발성염기질소 분석을 수행한 결과 부패도가 서로 다른 모든 시료에서 자동적정과 수동적정의 평균들 간에 유의수준 15%에서도 유의차가 인정되지 않았으며, 두 방법의 평균치들 사이에 높은 상관성이 확인되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.117-117
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• 2008

In MIM capacitor, poly-Si bottom electrode is replaced with metal bottom electrode. Noble metals can be used as bottom electrodes of capacitors because they have high work function and remain conductive in highly oxidizing conditions. In addition, they are chemically very stable. Among novel metals, Ru (ruthenium) has been suggested as an alternative bottom electrode due to its excellent electrical performance, including a low leakage of current and compatibility to high dielectric constant materials. Chemical mechanical planarization (CMP) process has been suggested to planarize and isolate the bottom electrode. Even though there is a great need for development of Ru CMP slurry, few studies have been carried out due to noble properties of Ru against chemicals. In the organic chemistry literature, periodate ion ($IO_4^-$) is a well-known oxidant. It has been reported that sodium periodate ($NaIO_4$) can form $RuO_4$ from hydrated ruthenic oxide ($RuO_2{\cdot}nH_2O$). $NaIO_4$ exist as various species in an aqueous solution as a function of pH. Also, the removal mechanism of Ru depends on solution of pH. In this research, the static etch rate, passivation film thickness and wettability were measured as a function of slurry pH. The electrochemical analysis was investigated as a function of pH. To evaluate the effect of pH on polishing behavior, removal rate was investigated as a function of pH by using patterned and unpatterned wafers.

• Journal of information and communication convergence engineering
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• 제20권1호
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• pp.49-57
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• 2022

Fertilizers have long been used to increase crop yields; however, farmers are still having difficulties in managing fertilizers for growing crops as well as economic problems. The conventional method of soil sampling and laboratory analysis to determine soil pH is time consuming and costly; therefore, a portable pH sensor is developed to characterize spatial or temporal variability within fields via rapid and dense data acquisition. The portable pH sensor comprises an electrode unit, a portable console, and a USB connector. The soil water content (SWC) and electrical conductivity (EC) affect the electrical resistance of soil. An artificial test soil is performed to evaluate the effect of SWC and EC on soil pH. The test results show that stable pH measurements are achieved at SWCs greater than 20 mL (16.3%). Regardless of the SWC, the electric potential difference (EPD) remains at 2.5 g of NaCl. As the EC increases in the soil samples, the EPD increases.

• 대한환경공학회지
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• 제31권12호
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• pp.1081-1088
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• 2009

Rhodamine B (RhB)의 제거를 위해 철 전극을 이용한 전기응집 (EC) 공정의 성능에 대해 연구하였다. RhB 제거 효율에 대한 전극 물질 (알루미늄, 철), 전류밀도, NaCl 첨가량, 초기 pH 및 초기 염료 농도와 같은 운전인자의 영향을 연구하였다. 이들 운전 인자에 대한 최적 운전 범위는 실험을 통하여 결정되었다. 희생 전극 물질로서 철 전극의 성능이 알루미늄 전극보다 우수하였다. 최적 전기분해 시간, 전류밀도, NaCl 첨가량 및 pH는 각각 10 분, 1630 A/$m^2$, 4 g/L 및 중성의 pH 이었다. 최적의 공정 조건하에서 RhB 농도가 230 mg/L인 조건에서 RhB는 효과적으로 제거되었고 (> 93.4%), RhB의 COD도 역시 감소하였다(> 88.9%). RhB의 색도와 COD 제거에 대한 상기 조건에서의 전기 에너지 소비량은 각각 10.3 and 10.8 kWh/kg RhB으로 나타났다. 전기응집 공정은 RhB와 같은 염색폐수 처리에 효과적인 것으로 나타났다.

• 대한화학회지
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• 제32권4호
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• pp.333-341
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• 1988

Cytosine에 대한 bio-electrode는 $NH_3$ 기체감응기에 Proteus mirabilis 와 Citrobacter freundii 박테리아를 고정하여 조립하였다. cytosine deaminase를 포함하는 박테리아는 cytosine 1분자를 $NH_3$ 1분자로 전환시킨다. Proteus mirabilis 박테리아 전극의 감응은 0.2M phosphate 완충용액, pH 8.4에서 $1.0{\times}10^{-3}\;-\;7.0{\times}10^{-3}$M직선범위와 45-48 mV/decade의 감응기울기를 가진다. Citrobacter freundii박테리아 전극의 감응은 0.05M phosphate완충용액, pH 7.6에서 $7.0{\times}10^{-5}\;-\;7.0{\times}10^{-3}$M 직선범위와 48 mV/decade의 감응기울기를 가진다. 이 전극을 pH, 온도, 완충용액, 박테리아의 양, 방해물질, 무기염류의 영향과 전극의 수명을 조사하였다.