• The Korean Journal of Physiology
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• 제3권1호
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• pp.19-28
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• 1969

Skin temperatures on 10 sites and rectal temperature at every 10 minutes, oxygen consumption at every 20 minutes were measured on 18 male subjects (ages between 14 and 47 years) after exposure to cold air at $15^{\circ}C$ for two hours in a climatic room. Total body fat measured by means of a skinfold method and ratio of body surface area (S) to body volume (V), S/V, were utilized as basis of observations. Surface area was calculated after DuBois equation and body volume was calculated by our original formula. In influencing on the heat loss from the body core to the cold environment, % fat showed inverse relations, whereas, S/V ratio showed direct relations. Thus these two factors acted antagonistically on the body heat loss. Local skin temperatures showed negative correlations with skinfold thickness on the same site, nemaly, on chest, r=-.567; on back, r=-.507; and on upper arm, r=-.353. The other 7 skin sites showed low correlations with % fat. Minimum mean weighted skin temperature (MWST) showed a negative correlation (r=-.443) with % fat, and showed no correlation with S/V ratio. Oxygen consumption in the cold air at $15^{\circ}C$ increased from the first measurement at 20 minutes after exposure and maintained the same increasing trend up to 120 minutes. ${\Delta}T_R$ was greater in tile lean subjects who showed a greater % change in oxygen consumption. The antagonistic actions of % fat and S/V ratio on the heat loss were manifested by observations as follows: minimum rectal temperature was higher In fat subjects (r=.600) and lower in subjects with a greater S/V ratio (=-.582), ${\Delta}T_R$ was smaller in fat subjects (r=-.738) and greater in subjects with a greater S/V ratio (r=.618). Temperature difference between body core and skin surface (minimum rectal temperature minus minimum MWST) showed a positive correlation with % fat (r=.600) and a negative correlation with S/V ratio (r=-.881). Decrease in the mean body temperature and heat debt, respectively, showed negative correlations with % fat and positive correlations with S/V ratio.

• 한국의학물리학회지:의학물리
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• 제11권2호
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• pp.101-107
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• 2000

펄스옥시메트리는 서로 다른 두 파장의 빛을 이용하여 동맥혈의 산소포화도를 측정하는 비침습성의 광에 의한 측정 방법이다. 동맥혈의 맥동성분은 정맥혈, 피부 그리고 기타의 비맥동성분들에 의해 감쇠되는 직류 성분에 중첩되어 있다. 본 논문에서는 맥동 성분의 적분비를 이용하여 산소포화도를 계산하는 알고리즘을 사용하였다. 알고리즘에서는, 심장의 수축과 관련되는 맥동신호의 1/2 싸이클만을 이용한다. 이용하는 시간은 1 cycle의 약 1/4이다. 1/4 주기를 이용하는 본 알고리즘은 기존의 방식과 유사한 결과가 나타났다. 신호의 진폭이 낮고, 시간의 점유가 많은 부분을 계산에서 배제했기 때문에, 동잡음의 영향이 감소되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제19회 학술발표대회 논문초록집
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• pp.18-18
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• 2002

A project where the TPUs(Turbo Pump Units) for 10tf-thrust oxygen/methane LRE (Liquid Rocket Engine) are under development is being implemented to include an experimental combustion chamber developed. In the process of it, we introduced the power-balanced engine cycles in order to substantiate concepts of the engine using the combinations of the propellants. Accordingly, the main engine parameters of nominal operating mode are resulted from the 1-Dcalculations and it is found that the regulators are needed for controlling the expected pressure levels in the characteristics of propellant mixture ratio and thrust supposing the regulator is set to analogue-typed one which is easy to develop.The technical requirements like the nominal flow rate, its deviations expected and the pressure difference In need helped the several main characteristics of regulators to be determine in this stage. Here, a dozen of deviation values in the main parameters related to engineoperation are taken into independent consideration and accepted to the results for additional regimes of the regulators.Finally, we can determine the scheme and the primary dimensions along with the calculation design of the spring acceptable for general configuration which can definitely forwarded to the autonomous tests of the aggregates, The obtained data in further will be used for successive refinement of operating mode of the engine.

• Ocean Science Journal
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• 제43권1호
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• pp.39-48
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• 2008

Tritium ($^3H$ or T) has been produced mostly by atmospheric nuclear weapon tests, and entered the ocean in the form of water (HTO). As tritium exists as water itself, it has been regarded as an ideal tool to study the transport of water masses. In April 2001 we collected water samples in the western Japan Basin (WJB) for tritium and helium measurement. The timely sampling provided direct evidence of the bottom water formation, resulting in the drastic increase in tritium concentration from 0.3 TU in 2000 to 0.67 TU in 2001. Considering that the new bottom waters were found mostly in the WJB, it implies that maximum 1% of the whole bottom layer below 2600 m should be replaced with the surface water during the severely cold winter 2000 2001. $^3H-^3He$ age, showing the elapsed time since the water left from the surface, can be used to calculate oxygen utilization rate by dividing AOU by the age. Under the condition of 90% oxygen saturation in the surface water, the integration of OUR in the water column below 200 m yields net oxygen consumption of 12 mol $(O_2)m^{-2}yr^{-1}$, which corresponds to the export production of $99\;g\;C\;m^{-2}yr^{-1}$. This estimate is comparable to a previous estimate based on satellite data and implies that the ratio of export to primary production(f-ratio) is as high as 0.5 in the WJB.

• 한국진공학회지
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• 제9권4호
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• pp.428-435
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• 2000

정전 탐침을 이용하여 유도 결합형 반응기에서 발생하는 산소 플라즈마의 음이온 발생 특성을 관찰하였다. 입력전력과 운전압력 조건에 따른 산소 플라즈마에서 electronegative 음이온 플라즈마의 입력전력과 운전압력에 따른 정전 탐침에 흐르는 포화 양 전류 대 포화 음 전류(전자 전류와 음 이온 전류의 합)의 전류 비율과 플라즈마 부유 전위와 플라즈마 전위 차의 변화로부터 음이온 발생 특성관찰을 하였다. 전류비의 증가와 전위차 값의 감소는 입력전력이 증가함에 따라 약 30∼60 mTorr 운전압력 영역에서 나타났으며 이 조건에서 음이온의 발생량이 증가함을 의미하고, 플라즈마내의 이온들은 음이온과 재결합에 의한 손실이 증가하여 플라즈마 밀도가 감소함을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.10-14
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• 2005

Zinc Oxide(ZnO) thin films on Si (100) substrates were deposited by RF magnetron reactive sputtering. The characteristics of zinc oxide thin films with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance were investigated. To analyze a crystallographic properties of the films, $\theta/2{\theta}$ mode X -ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity, and surface roughness highly depended on Ar/$O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7\;{\Omega}cm$ was obtained at a working pressure of 10 mTorr with Ar/$O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with Ar/$O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.173-176
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• 2010

75톤급 가스발생기 기술검증시제에서 나타난 산화제 분사기 차압의 증가 원인을 파악하기 위하여 축소형 가스발생기를 설계, 제작하였다. 설계점 및 탈설계점 시험 조건을 포함한 총 6회의 연소시험을 성공적으로 수행하였다. 연소시험 결과 연소압을 고정한 후 혼합비를 증가시킨 경우 연료 및 산화제 유량계수는 일정한 것으로 나타났으며, 혼합비를 고정한 후 연소압을 증가시킨 경우에도 연료 및 산화제 유량계수는 변함이 없는 것으로 파악되었다.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.617-624
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• 2000

Zinc Oxide(ZnO) thin films on Si(100) substrate were deposited by RF magnetron reactive sputtering. The charcteristics of ZnO thin films on argon/oxygen(Ar/O$_2$)gas ratios RF power and substrate temperature were investigated by XRD, SEM, and AFM analyses. C-axis preferred orientation resistivity and surface roughness highly depended on Ar/O$_2$gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of 9$\times$10$^{7}$ $\Omega$cm was obtained at a working pressure of 10 mTorr with Ar/O$_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with Ar/O$_2$=50/50 showed the excellent roughness value of 28.7$\AA$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.124-130
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• 2003

Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films, $\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity. and surface roughness highly depended on $Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with $Ar/O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with $Ar/O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

• 대한금속재료학회지
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• 제48권1호
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• pp.77-84
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• 2010

Annealing characteristics of an oxygen free copper (OFC) processed by differential speed rolling (DSR) were investigated in detail. An OFC sample with a thickness of hum was rolled to 35% reduction at ambient temperature without lubrication, varying the differential speed ratio from 1.0:1 to 2.2:1, and then annealed for 0.5h at various temperatures from 100 to $400^{\circ}C$. Different recrystallization behavior was observed depending on the differential speed ratio, especially in the case of annealing at $200^{\circ}C$ Complete recrystallization occurred in the specimens annealed at temperatures above $250^{\circ}C$ regardless of the differential ratios. The hardness distribution in the thickness direction of the rolled OFC sheets varied depending on the differential speed ratios. These annealing characteristics were explained by the magnitude of shear strain introduced during rolling.