• 반도체디스플레이기술학회지
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• 제15권1호
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• pp.70-75
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• 2016

GZO films prepared on ITO glasses were annealed at various temperatures in a vacuum condition to research the relationship between oxygen vacancies and optical properties. GZO films after annealing in a vacuum showed the various optical-chemical properties depending on the annealing temperatures and oxygen gas flow rate during the deposition. The oxygen vacancy of GZO film prepared by oxygen gas flows of 22 sccm increased with increasing the annealing temperatures, because of the extraction of oxygen by the annealing. But the intensity of photoluminance of GZO with 22 sccm decreased in accordance with the annealing temperature, because of the reduction of ionized charge carriers. The oxygen vacancy by the extraction of oxygen enhanced a depletion, so the widen depletion had the strong Schottky barrier and the PL intensity due to the low carrier density decreased.

• Journal of Electrochemical Science and Technology
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• 제13권2호
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• pp.261-268
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• 2022

In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 μS cm^-1 and chemical oxygen demand of 250 mg L^-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.

• 조명전기설비학회논문지
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• 제25권11호
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• pp.103-112
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• 2011

This paper is tried to analysis the optical emission spectroscopy related to the position of inductive load coil and flow rates of methane and oxygen in the RF inductive plasma process. According to the position of load coil, peak of $H_{\alpha}$, $H_{\beta}$, and CH were appeared strongly at the middle position of the coil and it decreased both direction. The electron temperature was approximately 0.9[eV] at that position. Emission intensities of $H_{\alpha}$, $H_{\beta}$, and CH increased linearly by increasing input power. In addition, intensities of $H_{\alpha}$ and $H_{\beta}$ increased by increasing the flow rate of oxygen. It might be ascribed that the oxygen species were bonded with $C_nH_m$ by suppressing the combination with hydrogen atoms. Consequently, the optimal position of the inductive coil is decided to the intermediate position between 4th and 5th turns, the wanted carbon thin-film is possible to deposit by controlling flow rates of methane and oxygen.

• Corrosion Science and Technology
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• 제12권2호
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• pp.85-92
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• 2013

This work is concerned with an evaluation of dynamic boric acid corrosion (BAC) of low alloy steel for reactor pressure vessel of a pressurized water reactor (PWR). Mockup test method was newly established to investigate dynamic BAC of the low alloy steel under various conditions simulating a primary water leakage incident. The average corrosion rate was measured from the weight loss of the low alloy steel specimen, and the maximum corrosion rate was obtained by the surface profilometry after the mockup test. The corrosion rates increased with the rise of the leakage rate of the primary water containing boric acid, and the presence of oxygen dissolved in the primary water also accelerated the corrosion. From the specimen surface analysis, it was found that typical flow-accelerated corrosion and jet-impingement occurred under two-phase fluid of water droplet and steam environment. The maximum corrosion rate was determined as 5.97 mm/year at the leakage rate of 20 cc/min of the primary water with a saturated content of oxygen within the range of experimental condition of this work.

• 멤브레인
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• 제14권2호
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• pp.142-148
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• 2004

본 연구는 호흡부전환자를 위한 진동형 혈관 내 폐 보조장치를 사용하여 산소전달효율을 향상시키기 위한 연구이다. 유량은 점프와 유량을 사용하여 조정하였다. 가진 장치는 압전 진동자, 함수 발생기와 전력 증폭기로 구성하였다. 기체의 유량은 120 cm 길이의 중공사를 통하여 6 L/min까지 하였으며 압전 진동자로 가진 하였다. PVDF 센서와 FRF를 사용하여 VIVLAD에서 발생하는 주파수를 검출하였다. 실험결과, 최대 진폭이 발생하고 중공사들에 진동이 전달되어 최대 산소전달속도가 발생함을 확인할 수 있었다. 이 최대 진폭은 다양한 유속과 각각의 모듈에서 35 Hz 영역에서 발생함을 확인할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.774-779
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• 2012

MILD(Moderate and Intense Low Oxygen Dilution) 연소는 연소 가스의 재순환을 이용하여 고온 형성을 최대한 억제하고 질소산화물의 발생을 저감하는 동시에 연소로의 내부 온도 균일화를 통한 열 이용 효율을 향상시킬 수 있는 연소기술이다. 본 연구에서는 원추형 연소로에서 연료 유량은 고정하고 공기 유량으로 당량비(${\Phi}$)를 조절하고 배기가스를 측정하여 MILD 연소특성을 도출하였다.

• 대한화학회지
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• 제48권6호
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• pp.663-666
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• 2004

• 대한기계학회논문집B
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• 제39권10호
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• pp.817-824
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• 2015

본 논문은 수직 오리피스 노즐의 유동 및 물질전달 특성에 대한 실험적 연구를 목적으로 한다. 구동유체 및 부유체의 유량, 용존산소 농도 그리고 소비 전력을 측정하였으며, 고속 카메라를 이용한 직접 촬영 기법으로 수직 혼합유동의 가시화 이미지를 획득하였다. 측정자료를 이용하여 질량비, 총괄 산소전달 계수 그리고 물질전달 성능계수를 도출하였다. 구동압력이 증가하면 질량비는 약간 감소하는 반면에, 산소전달 계수와 소비전력은 증가하였다. 구동압력이 증가하고 질량비가 작아지면, 기포의 미세화가 촉진되고 확산도가 증대되기 때문에 산소 전달율이 증가하였다.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2221-2228
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• 2021

One-dimensional oxygen transport relation is indispensable to study the oxygen distribution in the LBE-cooled system with an oxygen control device. In this paper, a numerical research is carried out to study the oxygen transport characteristics in a gas-phase oxygen control device, including the static case and dynamic case. The model of static oxygen control is based on the two-phase VOF model and the results agree well with the theoretical expectation. The model of dynamic oxygen control is simplified and the gas-liquid interface is treated as a free surface boundary with a constant oxygen concentration. The influences of the inlet and interface oxygen concentration, mass flow rate, temperature, and the inlet pipe location on the mass transfer characteristics are discussed. Based on the results, an oxygen mass transport relation considering the temperature dependence and velocity dependence separately is obtained. The relation can be used in a one-dimensional system analysis code to predict the oxygen provided by the oxygen control device, which is an important part of the integral oxygen mass transfer models.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 춘계 학술발표강연 및 논문개요집
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• pp.62-62
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• 2002