• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.63-66
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• 2003

This study applied a hydrogeological field survey and isotope investigation to identify source locations and delineate pathways of groundwater contamination by nitrogen compounds. The infiltration and recharge processes were analyzed with groundwater-level fluctuation data and oxygen-hydrogen stable isotope data. The groundwater flow pattern was investigated through groundwater flow modeling and spatial and temporal variation of oxygen isotope data. Based on the flow analysis and nitrogen isotope data, source types of nitrate contamination in groundwater are identified. Groundwater recharge largely occurs in spring and summer due to precipitation or irrigation water in rice fields. Based on oxygen isotope data and cross-correlation between precipitation and groundwater level changes, groundwater recharge was found to be mainly caused by irrigation in spring and by precipitation at other times. The groundwater flow velocity calculated by a time series of spatial correlations, 231 m/yr, is in good accordance with the linear velocity estimated from hydrogeologic data. Nitrate contamination sources are natural and fertilized soils as non-point sources, and septic and animal wastes as point sources. Seasonal loading and spatial distribution of nitrate sources are estimated by using oxygen and nitrogen isotopic data.

• Korean Journal of Microbiology
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• v.10 no.3
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• pp.97-104
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• 1972

The extent of water pollution was investigated at 4 stations in Kyonggi Bay during the summer seasons in 1970 and 1971. The concentrations of dissolved oxygen, total hardness, ammonia, nitrate, nitrite, phosphate, chemical oxygen demand, salinity, biochemical oxygen demand, coliform bacteria and facel coli were examined together with the measurement of pH and transparency. The relationship between the extent of pollution and the distance from the Inchon Bay also was examined. The concentrations of biochemical oxygen demand, chemical oxygen demand, ammonia, nitrate, nitrite, phosphate, coliform bacteria nad fecal coli were all highest at station 1, and lowest at station 4. Values were somewhat higher at low tide level in general. On the contrary, dissolved oxygen concentration was highest at station 4 and lowest at station 1. The highest and lowest values of biochemical oxygen demand were 10.88 ppm at station 1 and 0.27 ppm at station 4. The chemical oxygen demand concentrations at station 1 and 4 were 1.90 ppm and 0.63 ppm. Ammonia concnetration at station 1 was 0.43 pp, and was nearly 5 times as much as that at station 4. The values were $2.45{\times}10^{-4}$ ppm at station 1, and $6{\times}10^{-4}$ ppm at station 4. Nitrite concnetration at station 1 was $3{\times}10^{-4}$ppm and was the highest, while the lowest was $9.45{\times}10^{-5}$ ppm at station 4. Phosphate value at station 1 too was the highest and was about 4 times as much as that at station 4. Coliform bacteria were most abundant at station 1, and were counted to be 1.$1.7{\times}10^{-5}$cells/ml. At station 4, the number greatly reduced to 8 * 10$^{2}$ cells/ml. The number of fecal coli at station 1 was $2{\times}10^{-4}$ cells/ml. But at station 4, no fecal coli was detected at high tide level. At low tide level, 3 cells/ml were counted at station 4. In all of these, the highest data were obtained at low tide level, while most of the lowest value, at high tide level. Generally, values at statio 1 were 3-5 times as much as those at station 4. Concentration of dissolved oxygen at station 1 was 0.366 mg-atoms/1 and was the lowest. The highest value was 0.420 mg-atoms/1 and was recorded at station 4. The highest at station 4, which certainly were believed to be the result of the dilution by the fresh water of the Han river flowing into the Inchon Bay. As we can see from the data above, the extent of pollution was highest at station 1, the nearest from Inchon harbor, and lowest at station 4, where is the farthest, Station 1 and 2 were proved to be much polluted, but station 3 and 4, not.

• Journal of Preventive Medicine and Public Health
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• v.5 no.1
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• pp.105-110
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• 1972

On 6 healthy adult males aged 20-30 years, oxygen pulse was observed during carrying sand bags weighing 10, 20 and 30 kg on a level treadmill running with speeds of 3, 4 and 5 km/hr. The results obtained were as follows. 1. Oxygen pulse during load carrying on a level treadmill was proportionately increased with an increase of work load, average oxygen uptake per minute. Regression equation of oxygen pulse (y: $m\iota$/beat) on the average oxygen uptake (x:$\iota$/min) required for each grade of work was expressed as y=3.34x+5.99, $s_{y.x}=0.858$). 2. Oxygen pulse reached the highest value 2-5 minutes after the start of load carrying, and thereafter it decreased gradually to some extend as the load carrying was continued. Rate of decrease in the oxygen pulse was greater in lighter works. 3. In lighter works requiring less than $2.0\iota/min$ of oxygen uptake, no difference in oxygen pulse could be seen between methods of carrying even when the same amount of load was carried. In heavier works requiring more than $2.0\iota/min$ of oxygen uptake, oxygen pulse was larger in case of carrying a load by embrace, in both hands and on head than on back or on shoulder.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.7-11
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• 1994

The free-livein nitrogen fixing bacterium, Arcobacter nitrofigilis which has been known to be a microaerophile, exhibited aerobic growth in brucella broth. In a level of oxygen equivalent to an air atmosphere (21% $O_2$), the maximum cell growth was observed in brucella broth. Low level of cell growth occurred in a level of low oxygen equivalent to lower than 2%, unless any other terminal electron acceptors other than oxygen were wupplied in brucella broth. Membrane-bound cytochrome b and c, and soluble cytochrome c were found. The growth in an aerobic atmosphere, little growth at low oxygen level, and occurrence of cytochrome c mean that this species is an aerobe and obtains energy using energy-yielding respiration.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.55-60
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• 2001

The effect of high energy B ion implantation and initial oxygen concentration upon defect formation and gettering of metallic impurities in Czochralski silicon wafer has been studied by applying DLTS( Deep Level Transient Spectroscopy), SIMS(Secondary ton Mass Spectroscopy), BMD (Bulk Micro-Defect) analysis and TEM(Transmission Electron Microscopy). DLTS results show the signal of the deep levels not only in as-implanted samples but also in low and high temperature annealed samples. Vacancy-related deep levels in as- implanted samples were changed to metallic impurities-related deep levels with increase of annealing temperature. In the case of high temperature anneal, by showing the lower deep level concentration with increase of initial oxygen concentration, high initial oxygen concentration seems to be more effective compared with the lower initial oxygen one.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.81-83
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• 2003

The present study attempted to observe what changes the supply of highly concentrated(30％) oxygen cause to people's ability and cerebrum lateralization of verbal cognition, compared to air of normal oxygen concentration(21％). The experiment consisted of two runs, one for verbal cognition test with normal air(21％ of oxygen) and for verbal cognition test with more oxygen in the air(30％ of oxygen). Functional brain images were taken form 3T MRI using the single-shot EPI method. There were more activations observed at the occipital, parietal, temporal, and frontal lobes, but there were no changes in cerebrum lateralization with 30％ oxygen administration. The result of task performance showed the accuracy increased at 30％'s concentration of oxygen rather than 21％'s. It is concluded that the positive effect on the verbal cognitive performance level by the highly concentrated oxygen administration was due to changeless increase of left and right cerebrum activation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.188-192
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• 2018

Surgery to increase cerebral blood flow is one of the treatment methods of cerebral infarction. However, invasive methods, such as surgery, may result in postoperative complications or side effects. In order to supplement this invasive method, non-invasive devices have been introduced that use human blood pressure to pressurize the extremities to increase cerebral blood flow. However, the problem of poor speed and accuracy was raised. In this paper, the perfusion index of each arm was measured by applying pressure to both arms using Blood Oxygen Level Sensor to improve the accuracy of measurement and measurement time. The pressure applied to the arm by 75% of the moment when it falls to the leg and the pressure calculated by using the pressure value obtained from the arm. Like the existing blood pressure measuring cerebral blood flow increasing device, the blood flow can be increased by more than 20% and the measurement time can be shortened, so that it can be selectively used for the patient with cerebral infarction.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.42-47
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• 2011

Going underwater is supposed to begin with the history of human beings. At first it was confined to relatively shallow level, less than several meters by holding breath. Recently, deep level diving has been necessary for such purpose as construction, maritime salvage, military operations, research and sports by using SCUBA(self-contained underwater breathing apparatus) equipment. As one goes down into water, the pressure on the diver is increased due to water pressure with depth, usually 1 atm for each 10 m water level. In deep water, mixed gas or nitrox(EAN, enriched air nitrox) could be applied for the divers lest they should get disease due to high pressure. Of these, the former is usually composed of oxygen and inert gas like helium or hydrogen, the latter contains higher oxygen content than that in normal air in which the oxygen concentration is designated by the character "EAN" followed by vol. % of oxygen, for example, "EAN 40" contains 40% of oxygen. In this case, a victim was found at the 39 m below the sea surface breathing air and nitrox in cylinder wrongly marked as EAN 36, which was analyzed to contain 63% of oxygen by GC/TCD. The cause of death could not be exactly related with the oxygen content in the nitrox cylinder, because the accurate depth for the victim to dive was not known, even though the victim was just found at the depth of 39 m. However, the wrongly marked nitrox could be believed to be the main cause of the death at the depth unless there happened any other accident except that during diving.

• Journal of Korean Academy of Nursing
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• v.13 no.2
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• pp.87-104
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• 1983

It has been well documented that animals exposed to cold show increased activity of thyroid gland. The calorigenic action of thyroid hormone has been demonstrated by a variety of in vivo and in vitro studies. According to Edelman et al., the thyroid thermogenesis is due to activation of energy consuming processes, especially the active sodium transport by the hormone in target tissues. If so, the increase in thyroid activity during cold exposure should induce increased capacity of sodium transport in target tissue and the change in tissue metabolism should be precisely correlated with the change in Na+_K+_ATPase activity of the tissue. This possibility was tested in the present study: in one series, changes in oxygen consumption and Na+_K+_-ATPase activity of liver preparations were measured in rats as a function of thyroid status, in order to establish the effect of thyroid hormone on the tissue respiration and enzyme system in another series, the effect of cold stimulus on the serum thyroid hormone level, hepatic tissue oxygen consumption and Na+_K+_ATPase activity in rats. The results obtained are as follows: 1. The Na+_dependent oxygen consumption of liver slices, the oxygen consumption of liver mitochondria and the Na+_K+_ATPase activity of liver preparations were significantly inhibited in hypothyroidism and activated in hyperthyroidism. Kinetic analysis indicated that the Vmax. of Na+_K+_ATPase was decreased in hypothyroidism and increased in hyperth)'roidism. 2. In cold exposed rats, the serum triiodothyronine (T₃) level increased rapidly during the initial one day of cold exposure, then declined slowly to the control level after two weeks. The serum thyroxine (T₄) level decreased gradually throughout the cold exposure. Accordingly the T₃/T₄ratio increased. The mitochondrial oxygen consumption and the Na+_dependent oxygen consumption of liver slices increased during the first two days and then remained unchanged thereafter The activity of the Na+_K+_ATPase in liver preparations increased during cold exposure with a time course similar to that of oxygen consumption. Kinetic analysis indicated that the Vmax. of Na+_K+_ATPase increased. 3. Once the animal was adapted to cold, induction of hypothyroidism did not significantly alter the hepatic oxygen consumption and Na+_K+_ATPase activity. These results indicate that: 1) thyroid hormone increases capacities of mitochondrial respiration and active sodium transport in target tissues such as liver; 2) the increased T₃level during the initial period of cold exposure facilitates biosynthesis of Na+_K+_ATPase and mitochondrial enzymes for oxidative phosphorylation, leading to enhanced production and utilization of ATP, hence heat production.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.95-100
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• 2020

Recently, the problem of hypoxia caused by jogging is attracting attention. To solve this problem, this paper proposed a new solution. This paper proved that as a vocalization method of reading aloud, it is possible to increase air intake and activate lung function to exchange more air and obtain more oxygen. Then, blood oxygen saturation was used as an evaluation index for the body's oxygen content level to prove its effectiveness. A photoelectric pulse oximeter developed on the basis of different light absorption principles in blood was used to test blood oxygen saturation. Experimental results show that a certain degree of hypoxia is induced when a lot of oxygen is required due to jogging. Therefore, it was proved that the new vocal breathing method by reading books can increase the blood oxygen saturation of the body and improve the hypoxia of the body. Reading vocal breathing is a simple and efficient oxygen saturation recovery breathing method.