• 제목/요약/키워드: Excess oxygen

검색결과 218건 처리시간 0.021초

헤마토크?????? 비율이 낮은 사람에 있어서 최대 산소 부채와 과잉젖산 사이의 관계 (Maximal Oxygen Debt, Lactate and Excess Lactate in Men with Low Hematocrit Ratio)

  • 김대성;남기용
    • The Korean Journal of Physiology
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    • 제2권2호
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    • pp.53-61
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    • 1968
  • Maximal oxygen debt, lactate and excess lactate were measured in 13 men with low hematocrit ratio before and after maximal exercise. Maximal exercise run was performed on a treadmill and the duration of run was 2 minutes 45 seconds in each subject. Hematocrit ratio ranged between 35 and 47%, the mean being 39.8%. The following results were obtained. 1. Maximal oxygen debt expressed on basis of body weight increased as the hematocrit ratio decreased. The correlation coefficient between the two was r= -0.770. 2. The time necessary for decreasing to 50% of total maximal $O_2$ debt(half time) became longer as the hematocrit ratio decreased. In normal men the half time was about 4 minutes and at the longest it was 12 minutes in men with the lowest hematocrit ratio. 3. The lactate concentration reached its peak value after 3 minutes of recovery. Thereafter, the time course of decrease in lactate concentration coincided roughly with that of respiratory oxygen debt curve. To reach to the resting level, however, it took longer time than that of respiratory oxygen debt. 4. Resting concentrations of lactate was 1.28 mM/l, pyruvate 0.13 mM/l and L/P ratio was 9.8. Peak value of ${\Delta}L$ after exercise reached to the value of 10.4 mM/l and ${\Delta}L/P$ reached 26.0. Peak excess lactate after exercise was 6.34 mM/l. 5. The part of oxygen debt accounted for by the oxygen equivalent of excess lactate was only 38.4%. A better relationship between lactate and oxygen debt was observed and the part of oxygen debt accounted for by the oxygen equivalent of lactate was 63.3%. 6. Peak value of lactate after maximal exercise increased as the hematocrit ratio decreased. 7. Respiratory oxygen debt of 100 ml/kg was accounted for by lactate more than 60% and only 30% was by excess lactate. 8. Excess lactate was not a good index of respiratory oxygen debt.

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순산소를 이용한 난류확산화염의 연소 특성에 관한 실험적 연구 (An experimental study on the combustion characteristics using pure oxygen in a turbulent diffusion flame)

  • 곽지현;전충환;장영준
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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    • pp.60-66
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    • 2001
  • Combustion using pure oxygen instead of air is an energy saving technology that can increase thermal efficiency by the improvement of burning rate and ultra high temperature flame, being used on the industrial spot. But information about it is not so enough yet. Flame figure, temperature distribution and emission concentration were measured with oxygen excess ratio and swirl number in a turbulent diffusion flame to investigate the combustion characteristics using pure oxygen. The results showed that flame figure became different as long as oxygen excess ratio varied and that concentration of NO and CO increased suddenly around ${\lambda}$=1.5.

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$CO_2$ 첨가에 따른 순산소 연소기의 연소특성에 관한 실험적 연구 (Experimental Study on the Oxygen Combustion Characteristics with $CO_2$ Feeding)

  • 서정일;곽영태;배수호;홍정구;이은도;신현동
    • 한국연소학회지
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    • 제10권2호
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    • pp.26-34
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    • 2005
  • The performance of oxygen combustion with $CO_2$ feeding was investigated in a pyrex tube furnace. The inverse type multi-hole burner was used for improving mixing and wide operating range. It introduced oxygen, fuel, and oxygen, respectively, from center tube to outer tubes. Oxygen combustion characteristics with excess oxygen ratio, oxygen feeding ratio, and $CO_2$ feeding flow rate were studied to optimize the operating condition and to apply the oxygen combustion with recirculation of flue gas to a real furnace. This paper presents results on the effect of $CO_2$ feeding flow rate on the structure of the flames and concentrations of NO and CO emissions. The visible flame length was shortest due to well mixing between fuel and oxygen when the oxygen feeding ratio was 0.25. The NO emission was reduced drastically regardless of excess oxygen ratio when the $CO_2$ feeding flow rate was larger than 15 lpm. The CO emission is varied by changing the $CO_2$ feeding flow rate but the CO emission characteristics is highly affected by excess oxygen ratio. When the excess oxygen ratio is below $\lambda=1.1$, the CO emission increased as the $CO_2$ feeding flow rate increased.

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역확산 다공 연소기에서 $CO_2$ 첨가에 따른 순산소 연소 특성에 관한 실험적 연구 (Experimental Study on the Effect of $CO_2$ Feeding on the Oxygen Combustion Characteristics by using Inverse Type Multi-hole Burner)

  • 서정일;곽영태;배수호;홍정구;이은도;신현동
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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    • pp.162-169
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    • 2005
  • The performance of oxygen combustion with $CO_2$ feeding was investigated in a pyrex tube furnace. The inverse type multi-hole burner was used for improving mixing and wide operating range. It introduced oxygen, fuel, and oxygen, respectively, from center tube to outer tubes. Oxygen combustion characteristics with excess oxygen ratio, oxygen feeding ratio, and $CO_2$ feeding flow rate were studied to optimize the operating condition and to apply the oxygen combustion with recirculation of flue gas to a real furnace. This paper presents results on the effect of $CO_2$ feeding flow rate on the structure of the flames and concentrations of NO and CO emissions. The visible flame length was shortest due to well mixing between fuel and oxygen when the oxygen feeding ratio was 0.25. The NO emission was reduced drastically regardless of excess oxygen ratio when the $CO_2$ feeding flow rate was larger than 15 lpm. The CO emission is varied by changing the $CO_2$ feeding flow rate but the CO emission characteristics is highly affected by excess oxygen ratio. When the excess oxygen ratio is below ${\lamda}=1.1$, the CO emission increased as the $CO_2$ feeding flow rate increased.

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과량의 니켈 첨가로 합성된 NiO와 Co3O4가 도핑된 La(CoNi)O3 페로브스 카이트의 알칼리용액에서 산소환원 및 발생반응 특성 (Characterization of NiO and Co3O4-Doped La(CoNi)O3 Perovskite Catalysts Synthesized from Excess Ni for Oxygen Reduction and Evolution Reaction in Alkaline Solution)

  • 버링;임형렬;이홍기;박경세;심중표
    • 한국수소및신에너지학회논문집
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    • 제32권1호
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    • pp.41-52
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    • 2021
  • NiO and Co3O4-doped porous La(CoNi)O3 perovskite oxides were prepared from excess Ni addition by a hydrothermal method using porous silica template, and characterized as bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for Zn-air rechargeable batteries in alkaline solution. Excess Ni induced to form NiO and Co3O4 in La(CoNi)O3 particles. The NiO and Co3O4-doped porous La(CoNi)O3 showed high specific surface area, up to nine times of conventionally synthesized perovskite oxide, and abundant pore volume with similar structure. Extra added Ni was partially substituted for Co as B site of ABO3 perovskite structure and formed to NiO and Co3O4 which was highly dispersed in particles. Excess Ni in La(CoNi)O3 catalysts increased OER performance (259 mA/㎠ at 2.4 V) in alkaline solution, although the activities (211 mA/㎠ at 0.5 V) for ORR were not changed with the content of excess Ni. La(CoNi)O3 with excess Ni showed very stable cyclability and low capacity fading rate (0.38 & 0.07 ㎶/hour for ORR & OER) until 300 hours (~70 cycles) but more excess content of Ni in La(CoNi)O3 gave negative effect to cyclability.

고효율 순산소 버너의 연소 특성에 관한 실험적 연구 (Experimental study on combustion characteristics of high efficiency oxy-fuel burner)

  • 김세원;안재현;김민수
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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    • pp.57-64
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    • 2002
  • This paper describes the results of a series of experiments executed by using two pilot-scale oxv-fuel burners are designed for maximum capacity of 50,000 kacl/hr, 300,000 kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, swirl vane angle and inlet oxygen temperature on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and inlet oxygen temperature. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, Optimum excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

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PEM 연료전지시스템의 동특성 해석 (Dynamic Analysis of PEM fuel cell system)

  • 김범수;전순일;임원식;박영일
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.353-356
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    • 2005
  • We developed a dynamic model of PEM fuel cell system which can analyze its transient response to dynamic load current. System components such as compressor, air cooler, humidifier, and stack were modeled based on their dynamic equations and performance maps by using Matlab Simulink platform. Through this simulation model, dynamic characteristics of fuel cell system including oxygen excess rat io, stack voltage, and system efficiency were shown. In addition to that, we briefly analyzed the humidity effect on cathode pressure and system efficiency, expecting that this model can be further used to optimize fuel cell system parameters just like operating pressure and temperature, humidity and oxygen excess ratio.

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고춧가루 섭취가 운동후초과산소섭취량에 미치는 영향 (Effect of red-pepper ingestion on excess post-exercise oxygen consumption in young women)

  • 황혜정;서혜정;임기원
    • 운동영양학회지
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    • 제14권2호
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    • pp.87-93
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    • 2010
  • PURPOSE. The purpose of this study was to investigate the effect of red-pepper ingestion on excess post-exercise oxygen consumption in young women. METHODS. The six female college students involved in this experiment. The subjects participated in two trials, standard meal (650 kcal) and standard meal +10 g red-pepper with 200 ml water. After the subjects allowed to have rest for 60 min, exercised by resistance program for 40 minutes. RESULTS. The excess post-exercise oxygen consumption (EPOC) was not affected by the red-pepper ingestion. However, post-exercise fat oxidation and plasma free fatty acid levels were higher in red-pepper trial than in control trial. CONCLUSION. Therefore, red-pepper ingestion before resistance exercise might be improve body fat reduction.

Can the Energy Costs of Speech Movements be Measured\ulcorner A Preliminary Feasibility Study

  • Bjorn Lindblom;Moon, Seung-Jae
    • The Journal of the Acoustical Society of Korea
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    • 제19권3E호
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    • pp.25-32
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    • 2000
  • The main question addressed in this research was whether an adaptation of a standard exercise Physiology Procedure would be sensitive enough to record excess oxygen uptake associated with speech activity. Oxygen consumption was recorded for a single subject during 7-minute rest periods and an automatic speech task, also 7-minutes long and performed at three different vocal efforts. The data show measurable and systematic speech-induced modifications of breathing and oxygen uptake patterns. The subject was found to use less power for normal than for soft and loud speech. This result is similar to findings reported by experimental biologists on the energetics of locomotion. However, more comprehensive feasibility studies need to be undertaken on a larger population before solid and detailed conclusions about speech energy costs are possible. However, it appears clear that, for experimental tasks like the present one, i.e., variations in vocal effort, standard exercise physiology methods may indeed offer a viable approach to recording excess oxygen uptake associated with speech movements.

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The Influence of Oxygen on Czochralski Growth of Oxide Single Crystals

  • D. S. Chung;Park, B. H.
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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    • pp.179-181
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    • 1997
  • When grown the oxide single crystal including Li-ion, optimum oxygen condition is needed. Color and crack are caused in single crystal according too the change in the condition of the oxygen. LiTaO₃ crystals grown from off-composition of congruent melt composition under oxygen deficieny condition didn't generate any crack. LiNbO₃. LiTaO₃ crystals grown from congruent melt composition under optimum oxygen condition caused pale yellow color or colorless with no crack. Color gradually became colorless and generated cracks according to Oxygen excess.

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