• Analytical Science and Technology
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• v.7 no.3
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• pp.371-378
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• 1994

The detection range of this galvanic oxygen sensor for oxygen concentration was 0.0% to 20.0%. By using gold or silver as cathode, reproducible response time and sensitivity to change of oxygen concentration were observed. The anode was Pb-Sn-Ca alloy. Oxygen selective permeable membrane was hydrophobic and porous Teflon film. The effect of the membranes varying in thickness have been studied on the temperature($10{\sim}50^{\circ}C$) and relative humidity(R. H 0~99%). Lead acetate buffer solution as the electrolyte has shown a high output voltage and longer life.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.52-53
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• 1995

현재 상용화 되어있는 산소/질소 분리용 고분자 분리막은 비교적 낮은 선택도를 가지고 있다. 즉, 이점은 확산도와 용해도를 조절함으로써 분리막의 투과선택도를 높일 수 있는 가능성을 보여주고 있으며 보다 높은 투과도와 투과선택도를 갖는 새로운 고분자 재료의 선택이 분리막을 통한 기체 분리나 그 상업적 이용에 절실히 요구되고 있다. PSf는 상용성, 화학적 내구력, 강도, 높은 유리전이온도와 우수한 기체투과성질을 가진 고분자로 분리막에 많이 응용되고 있다. Erb 등은 용매로 DMF(dimethylformamide)와 THF(tetrahydrofuran)를 사용하여 막을 제조하였다. 상부 흐름압력이 5atm일때 각 기체의 투과도 계수는, 헬륨이 11, 이산화탄소가 5.5, 메탄이 0.5, 질소가 0.2였으며, PSf막에 대한 각 기체의 투과는 Henry mode보다 Langmuir mode에서 더욱 우세하게 일어난다고 생각하였다. 또한 Ghosal 등은 PSf에 nitro기를 도입한 nitrated PSf의 투과특성을 조사하였다. 실험결과 nitro group이 치환된 PSf막이 nitro group이 없는 막에 비해 투과도는 낮았지만 선택도는 증가하였다. 구조가 다른 여러가지의 PSf막을 통한 기체 투과성질은 Ghem 등에 의해 밝혀졌다. Membrane-covered probes를 이용한 폴라로그램(polarogram) 방법은 산소를 측정하는데 가장 보편적인 방업ㅂ으로, 산소 탐침(oxygen probe)의 원리는 소위 효소 전극을 발전시키는데 이용되어 왔다. 효소전극은 산소와 실험하고자 하는 물질간의 특정한 효소반응에 기초를 둔 다양한 물질의 선택적 측정을 위한 것이다. 이때 센서에 응용되는 합성막은 산소에 대해 선택적인 투과를 해야하며, 상대적으로 높은 산소확산계수와 물에 대해서는 낮은 투과도를 가져야 한다. 높은 산소확산계수는 반응을 빠르게 하는 잇점이 있으며 물에 대한 낮은 투과도는 센서내의 전해질 물질을 유지보호하는 역할을 한다. 분리막이 산소전극에 이용될 경우 높은 산소 확산계수 이외에도 적절한 기계적 강도, 열적 안정성 등이 요구된다.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.1-7
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• 2001

Oxygen sensor taken from the aftertreatment systems of 4 vehicles which had been aged in domestic field examined for aging effects on emissions using a idel engine bench. also the artificial sensor signal generated by function generator was supplied to ECU, instead of oxygen sensor to simulate aging effects of oxygen sensor. This study shows that reduction of amplitude, deformation and shift of mean value of aged sensors seriously affect on the engine out emissions and the performance of TWC.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.85-91
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• 2000

Oxygen sensors taken from the aftertreatment systems of 4 vehicles which had been aged in domestic filed were examined for aging pattern using a idle engine bench. The sensors were then cut into each layers along their components and characterized for poisoning, surface area and morphology. This study shows that amplitude and mean value of aged sensors are seriously affected by high temperature and oil components of exhaust gas.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.123-131
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• 2002

In this paper, characteristics of cryogenic liquid oxygen was examined during cold flow of KSR-III main engine at each stage. The effect of venting was examined at the stage of cooling and at the pressurization stage, the interaction between nitrogen gas and liquid oxygen was also examined. The characteristic of liquid oxygen in the engine manifold was analyzed. The results showed that venting was the primary role at the cooling process and the interaction of nitrogen gas and liquid oxygen in the run tank is limited at the surface area. With the sampling rate of 1KHz static and dynamic pressure were measured in the rocket engine manifold and in the LOX supply equipment. 32.5mm and 38mm orifice were installed for the tests and pressure condition of liquid oxygen was 23Bar, 29Bar, 41Bar. Increase of orifice diameter and decrease of supply pressure reduced the perturbation of pressure in engine manifold.

• Journal of Sensor Science and Technology
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• v.10 no.3
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• pp.180-186
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• 2001

Recently, FET type dissolved oxygen sensor was proposed to overcome the disadvantages of the amperometric Clark-type sensor. The inherent problem of the proposed sensor, however, is the flow dependence of the sensor performances since the proposed sensor detects the pH change in close proximity to the working electrode. In this study, we decided the direction which minimize the flow effect in FIA(flow injection analysis) system. And a hydrodynamic buffer layer which can reduce the flow dependence were proposed. The suggested buffer-layers were formed onto sensing area and working electrode with mixed polymer matrix of TEOS(tetraethylorthosilicate) and DEDMS(diethoxydimethylsilane).

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.51-56
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• 2016

Oxygen is a key factor in aerobic reactions and most biological activities. Visualization of oxygen distribution of a chemical process or biological system has been a very challenging object despite of its significance and potential impact. To monitor and visualize the spatial distribution of oxygen concentration, various techniques such as electro-chemical probe, polarographic electrode, LIF(laser-induced fluorescence) and so on have been introduced. Oxygen planar optode which utilizes the oxygen quenching of fluorescence light is one of the currently available methods for time-resolved visualization of oxygen distribution on a planar surface. In this study, we utilized VisiSens oxygen planar optode system to visualize the spatial distribution of oxygen concentration on leaves of Korean azalea. As a result, temporal variation of oxygen concentration distribution caused by respiratory activity of the leaf could be quantitatively monitored.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.730-734
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• 2005

Flow injection analysis (FIA) system was developed to monitor glucose concentrations in biotechnological processes. A fiber optic oxygen sensor was used to determine consumption of oxygen concentration by reaction of immobilized glucose oxidase (GOD). The GOD was immobilized on VA-Epoxy carrier and integrated into FIA system. A calibration curve for glucose was obtained in the range of 0.5 $g/L{\sim}3.0$ g/L.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.266-269
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• 1995

In order to measure alcohol contents with speed and accuracy, alcohol sensor was prepared. Alcohol sensor was made by connecting with oxygen electrode after immobilized alcohol oxidase on nylon net with glutaraldehyde. Alcohol was determined by changing the rate of dissolved oxygen consumption using D.O. analyzer. Alcohol contents in alcoholic beverages were determined under the optimum conditions. The results were 0.71% in low-alcohol beverage, $4{\sim}5%$ in beers, 10.06% in wine, 16.12% in chungju, 25.71% in soju, and 6.18% in takju, respectively. The values by alcohol sensor showed an excellent correlation(r=0.999) with GC method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.473-476
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• 2010

본 논문에서는 심폐기능에 이상이 있는 중환자의 상태를 진단하기 위한 방법으로 Swan-Ganz Catheter를 체내에 삽입하여 심박 출량과 혼합정맥혈 산소포화도를 기존 장비들보다 정밀하게 측정할 수 있는 모듈을 개발하고자 한다. Swan-Ganz Catheter에는 두 개의 온도센서와 세 개의 압력센서를 포함하고 있으며 이를 통해 입력되는 센서 값을 세밀하게 수집하고 이를 기반으로 일회 심박출량, 전신 및 폐혈관저항, 산소소모량 등을 계산하여 환자의 상태를 보다 정확하게 진단 및 치료가 가능하게 한다.