• The Korean Journal of Physiology
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• v.2 no.1
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• pp.17-21
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• 1968

Total body oxygen uptake was measured in rats following hemorrhage (16 rats) and blood transfusion (7 rats) under light Nembutal anesthesia. Arterial blood Pressure measured on the tail artery decreased or increased following hemorrhage or transfusion. No direct relationship was observed between arterial blood pressure alteration and oxygen intake variation. Hematocrit ratio which changed after hemorrhage or transfusion showed a direct relationship with oxygen intake. Decrease in hematocrit ratio resulted in a decrease in oxygen intake of rats. The correlation coefficient between decrement of hematocrit ratio and decrement of oxygen intake was r=.56. The correlation coefficient between increment of hematocrit ratio and increment of oxygen intake was r=.86. Thus it was concluded that alteration in oxygen intake was limited by the systemic oxygen transport capacity of blood.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.2
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• pp.91-96
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• 1994

Intake gases other than air, which is composed of oxygen, nitrogen, carbon dioxide, and argon, are used to study their effects on the performance of the diesel engine experimentally. The engine is operated at constant speed and fixed fuel injection timing, and cylinder pressure and heat release rate are measured at various intake gas compositions. The results show that increase of oxygen concentration improves the performance of the engine generally. The adverse effect is observed when the oxygen concentration is increased over the critical oxygen concentration of this test, mainly because of the over-shortened ignition delay. Increase of carbon dioxide concentration degardes the performance of the engine, mainly due to the lower specific heat ratio of carbon dioxide. Adding argon gas to the intake gas improves the overall performance. Finally, it is found that two most influencing factors affecting the performance of the diesel engine in this study are ignition delay and speific heat ratio of the intake gas.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.6
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• pp.679-687
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• 2002

In this study, a cycle simulation using a two-zone model is carried out to investigate the effect of intake charging conditions such as oxygen concentration, temperature and pressure on NO emissions in a DI diesel engine. The model is validated against measurements in terms of cylinder pressure, torque, BSFC and NOx emissions with 2902 cc DI diesel engine. Calculated results can be summarized as follows. The oxygen concentration in the intake charge is decreased with increasing of EGR rate and equivalence ratio. As the intake oxygen concentration is reduced, the combustion pressure and the burned gas temperature decrease and, as a result, NO formation decreases. Also, the results show that as the intake pressure increases and the intake temperature decreases, NO emissions are effectively reduced.

• Journal of Energy Engineering
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• v.14 no.2 s.42
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• pp.73-81
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• 2005

An Experimental study was conducted to investigate the effective way for fuel consumption improvement in radiant tube burner heating system used in steel manufacturing process. To find effectiveness of increase of temperature and oxygen fraction of intake air on fuel consumption, the model radiant tube burner heating system with recuperator was designed to be able to adjust temperature and oxygen fraction of intake air, and was operated under various conditions with oxygen concentration in exhaust gas changed. The results show that burner chamber temperature was increased about $10\%$ of intake air temperature increase. so it was difficult to expect fuel consumption improvement. But only 1 or $2\%$ increase of oxygen fraction in intake air made a significant improvement in fuel consumption even though it made much NOx emissions also. Therefore, if NOx emissions is controlled under regulation with burner modification, it is expected that increase of oxygen fraction in Intake air is effective way to improve fuel consumption.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.105-111
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• 1998

My prior questionnaire has applied to 12 male and 29 female adults over 30-69 years old suffering from lumbago fer 6 months at least or having diagnosis of lumbago. I had the following conclusions from physical characteristics and cardiopulmonary capacity of lumbago Patients caused by obesity 1) The rate of lipids in the body was rotated to the maximum heart rate in the male group of lumbago patients (P<0.01). 2) The rate of lipids in the body was related to the maximum intake of oxygen(O2) in the male group of lumbago patients(P<0.01). 3) The maximum heart rae was related to the maximum intake of oxygen in the male group of lumbago patients(P<0.01). 4) The rate of lipids in the body was related to the maximum intake of oxygen in the female group of lumbago patients(P<0.05). 5) The rate of lipids in the body showed no relation to the maximum heart rate in the female group of lumbago patients(P>0.05). 6) The maximum heart rate was related to the maximum intake of oxygen in the female group of lumbago patients(P<0.01). 7) The cardiovascular system showed no relation te the function of the lungs in the male and female groups of lumbago patients(P>0.05) 8) The lung capacity per second of lumbago patients(FEV $1.0\%$) measured less than normal adults. 9) The maximum intake of oxygen(V02max) and heart rate was less than normal adults. Thus I summarized the conclusion so follows: the cardiovascular system of lumbago patients showed no relation to their pulmonary function, and the rate of lipids in the body Showed a correlation with the maximum intake of oxygen but the rate of lipids in the body showed no relation to their pulmonary function.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.83-90
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• 1967

In order to evaluate the accuracy of the measurement of maximal oxygen intake (MOI), the MOI in seven subjects was determined 3 to 4 times in each individual. Following a 10 minute warm-up on treadmill (4.3 km/hr with 9 degree grade), the subject was asked to run at a speed of 8.73 km/hr on treadmill for a period of 3 minutes at a given grade which was elevated in a step-wise manner from zero to the level of exhaustion. Following a 3 minute run, the subject was allowed to rest for a period of 3 to 5 minutes. During each period of running, several cardio-pulmonary functions were determined and the range of variability for each measurement was computed. The oxygen consumption during the maximal work load was taken as the MOI. The results may be summarized as follows: (1) The minute volume, the oxygen consumption and the heart rate increased linearly until the grade was elevated to 9 degree above which these values were leveled off. (2) The minute volume and the heart rate during maximal exorcise were $87.4{\pm}8.10\;1/min\;and\;187{\pm}3.7$ per minute, respectively. (3) The maximal oxygen intake which corresponds to the oxygen consumption during maximal exercise was averaged to 3.04 1/min. (4) The coefficient of variance for the maximal oxygen intake was 6.32% while the corresponding values for the minute volume and the heart rate during maximal exercise were 5.22 and 2. 14%, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.3
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• pp.70-78
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• 2000

The effects of recirculated exhaust gas on the characteristics of ;$NO_x$ and soot emissions under a wide range of engine load have been experimentally investigated by a water-cooled, four-cylinder, indirect injection, four cycle and marine diesel engine operating at two kinds of engine speeds. The purpose of the present study is to develop the EGR control system for reducing $NO_x$ and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions, and a novel diesel soot removal apparatus with a cylinder-type scrubber for the experiment system which has 6 water injectors(A water injector is made up 144 nozzles with 1.0mm in diameter) is specially designed and manufactured to reduce the soot contents in the recirculated exhaust gas to intake system of the engines. The intake oxygen concentration obtained by the intake air flow and the oxygen concentration in the recirculated exhaust gas, and the exhaust oxygen concentration measured in exhaust manifold are used to analyse and discuss the influences of EGR on NOx and soot emissions. The experiments are performed at the fixed fuel injection timing of $15.3^{\circ}$ BTDC regardless of experimental conditions. It is found that $NO_x$ emissions decrease and soot emissions increase owing to the drop of intake oxygen concentration and exhaust oxygen concentration as EGR rate rises. Also, one can conclude that it is sufficient for the scrubber EGR system with a novel diesel soot removal apparatus to reduce $NO_x$ emissions, but not to reduce soot emissions.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.49-58
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• 1994

A study on the performance of a Diesel engine with various intake gas compositions other than that of air are performed experimentally. In this study, the concentrations of each of oxygen, nitorgen, carbon dioxide, and argon are changed and their effects on the performance of the engine are investigated parametrically. The experiments are performed at constant engine speed condition, and main measured parameters are cylinder pressure, intake gas compositions, fuel consumption rate. Increase of oxygen concentration up to 24% improved the performance of the engine generally. The adverse effect was observed when the oxygen concentration was increased over 24%. Increase of carbon dioxide concentration degraded the performance of the engine, mainly due to the lower specific heat ratio of carbon dioxide. Adding argon gas to the intake gas improved the overall performance. Finally, it is found that two most influencing factors affecting the performance of the Diesel engine in this study of intake gas composition variation are ignition delay and specific heat ratio of the intake gas.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1247-1254
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• 2000

The effects of recirculated exhaust gas on the characteristics of $NO_x$ and soot emissions under a wide range of engine load have been experimentally investigated by a water-cooled, four-cylinder, indirect injection, four cycle and marine diesel engine operating at two kinds of engine speeds. The simultaneous control of $NO_x$ and soot emissions in diesel engines is targeted in this study. The EGR system is used to reduce $NO_x$ emissions, and a novel diesel soot removal device with a cylinder-type scrubber for the experiment system which has 6 water injectors(A water injector has 144 nozzles in 1.0 mm diameter) is specially designed and manufactured to reduce the soot contents in the recirculated exhaust gas to intake system of the engines. The intake oxygen concentration and the mean equivalence ratio calculated by the intake air flow and fuel consumption rate, and the exhaust oxygen concentration measured are used to analyse and discuss the influences of EGR rate on $NO_x$ and soot emissions. The experiments are performed at the fixed fuel injection timing of $15.3^{\circ}$ BTDC regardless of experimental conditions. It is found that $NO_x$ emissions are decreased and soot emissions are increased owing to the drop of intake oxygen concentration and exhaust oxygen concentration, and the rise of equivalence ratio as the EGR rate rises.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.142-154
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• 1998

The effects of recirculated exhaust gas on the characteristic of soot emissions have been investigated by using an eight-cylinder, four-stroke, direct injection and water-cooled diesel engine operating at several loads and speeds. The experiments in this study are carried out at the fixed fuel injection timing of $38^{\circ}$ BTDC regardless of experimental conditions. The intake oxygen concentration and the mean equivalence ratio calculated by the intake air flow and fuel consumption rate are used to analyze and discuss the influences of EGR rate on soot emissions. Results of this study indicate that soot emissions increase owing to the drop of intake oxygen concentration and the rise of equivalence ratio as the EGR rate increases at a given engine load and speed, especially the high load.