• Clinical and Experimental Pediatrics
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• v.54 no.9
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• pp.359-362
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• 2011

There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation ($SpO_2$) is 90 to 93% with an intermittent review of the correlation between $SpO_2$ and the partial pressure of arterial oxygen tension ($PaO_2$). Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

• Journal of Aerospace System Engineering
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• v.3 no.3
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• pp.39-44
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• 2009

Humans rely on the availability of a supply of gaseous oxygen for survival. If the minimal requirements for oxygen are not met, both mental and physical abilities and performance are degraded rapidly. So oxygen systems are required for the aircraft operating at high altitude to prevent physical and psychological problems, or loss of consciousness in an aircraft pilot, flight crew, or passengers. If oxygen system and equipments are to be included in the type design of an airplane, applicant should consider applicable airworthiness requirements and operating rules. In this paper we analyze the various oxygen system requirements for the type of aircraft, oxygen system, and operating conditions.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.763-773
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• 2010

The removal efficiencies and a total oxygen transfer coefficient for food waste leachate(FWL) were estimated by using Jet Loop Reactor(JLR). Pure oxygen was used instead of air to improve oxygen concentration in the JLR for high total chemical oxygen demamd(TCOD) in FWL. In JLB, in order to examining the oxygen transfer characteristic, the circulation flowrate and oxygen flowrate were controlled with 7~10 L/min(1.5 L/min interval) and 0.2~0.5 L/min (0.1 L/min interval) and we experimented according to the each condition. As a result, Oxygen uptake rate(OUR) and oxygen transfer rate could be maximized than the oxygen flowrate to increase the circulation flowrate. In addition, it determined that JLR using the pure oxygen which can obtain the greatest oxygen transfer rate as it was the high-concentration organic wastewater like the food waste leachate through the continuous experiment was appropriate.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.193-198
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• 2005

Changes in visuospatial cognitive performance, blood oxygen saturation and heart rate due to the highly concentrated oxygen administration were observed in this study. Six male ($25.8 \pm$1.0) and six female (($23.8 \pm$ 1.9) adults were asked to perform 20 visuospatial tasks with the same level of difficulties by supplying two different oxygen levels (21%, 30%). Experiment consisted of Rest1 (1 min.), Control (1 min.), Task (4 min.), and Rest2 (4 min.) and physiological signals such as blood oxygen saturation and heart rate were measured through each stage. The result showed the accuracy of task performance increased significantly at 30% oxygen concentration compared with 21%, which means oxygen supply has positive effects on visuospatial cognitive performance. When 30% oxygen was supplied, blood oxygen saturation during control and task phases was increased and heart rate was decreased compared with 21%. It means that 30% oxygen can stimulate brain activities by directly increasing the actual level of blood oxygen concentration during cognitive performance, and enough oxygen supply during cognitive performance make heart rate decrease.

• Toxicological Research
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• v.19 no.2
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• pp.99-104
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• 2003

This study was aimed to evaluate the effect of oxygen on motor activity and toxicity in male mice. The modified Porsolt forced swim test (FST) was used and the distance and time of movement by mice were analyzed in 15。C water bath for 20 minutes using the automatic Ethovision videotracking system. Analyses were carried out before and after 20 minutes of exposure to 10％-70％ concentration of normobaric oxygen. The effects of inspired oxygen tension on the distance and time of movement showed the similar trends, but changes in distance were more prominent. Both the distance and time of movement increased after exposure to 30％ and 40％ oxygen concentration. The distance and time of movement also increased upon exposure to 50％ and 60％ oxygen. In contrast, increases En movement and time under exposure to 21％ oxygen concentration were suppressed when exposed to over 50％ oxygen concentration. With exposure to 10％ oxygen, there was a significant decrease in the distance of movement and a slight suppression of movement time. During the swim test, 12.5％, 37.5％, and 87.5％ of the mice drowned after exposure to 10％, 60％, and 70％ oxygen concentration, respectively. These results suggest that motor activity can be enhanced by inspired oxygen up to 40％ concentration. When hypoxic and hyperoxic oxygen exposure over 50％, motor activity is reduced and toxicity may be induced.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.4
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• pp.404-411
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• 2016

To select appropriate oxygen carrier candidates for chemical looping combustion, reduction characteristics of seven oxygen carriers were measured and discussed using three different reduction gases, such as $H_2$, CO, and $CH_4$. Moreover, attrition losses of those oxygen carriers also measured and compared. Among seven oxygen carrier particles, OCN703-1100 and NiO/bentonite particles showed higher oxygen transfer capacity than other particles, but these particles showed more attrition loss than other particles. C14 and C28 particles which used as cheap oxygen carriers in European country showed lower oxygen transfer capacity and less attrition loss. Based on the experimental results, we could select OCN717-R1SU, NC001, and N002 particles as candidates for future works because these oxygen carriers showed enough oxygen transfer capacity and good attrition resistance.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.443-451
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• 2001

In order to investigate what kind of response anaerobic bifidobacteria has on oxygen stress, five oxygen-tolerant bifidobacteria were isolated from human fecal samples. All were temporarily identified as Bifidobacterium longum through an analysis of carbohydrate utilization patterns and cellular fatty acid profiles. In the presence of oxygen, the lag phase became extended and the cell growth was suppressed. Bifidobacterial cell was able to remove dissolved oxygen in an early stage of growth and to overcome oxygen stress to a certain extent. The cell became long n size and showed a rough surface containing many nodes which were derived from abnormal or incomplete cell division. Cellular fatty acid profiled changed remarkably under a partially aerobic condition, so that the carbon chain of cellular fatty acid became short. All the dimethyl acetals originated from plasmalogen were reduced, any cyclopropane fatty acid, 9, 10-methyleneoctadecanoic acid ($C_{19:0}cyc9,10$), was increased remarkably. Oxygen stress induced a 5.5 kD protein in B. longum JI 1 of the oxygen-teolerant bifidobacteria, that was named Osp protein, and its N-terminal amino acid sequence was as follows: unknown amino acid-Thr-Gly-Val-Arg-Phe-Ser-Asp-Asp-Glu. Therefore, the oxygen-tolerant bifidobacteria seemed to defend against oxygen stress byincreasing the content of short fatty acid and cyclopropane fatty acid, and induction of an oxygen stress protein, but not the plasmalogen.

• IE interfaces
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• v.18 no.2
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• pp.178-183
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• 2005

In this study, changes in memory performance, blood oxygen saturation and heart rate according to 30% concentration oxygen supply were observed. Ten healthy male and female college students (male:$25.8{\pm}0.8$ years, female: $24.2{\pm}1.9$ years) participated in the study. The experiment was performed as Rest (1min.), Control task (1min.), Word presentation (1min.), Reaction time task (1min.), Distractor (2min.), and Word recall (1min.) and the physiological signals such as blood oxygen saturation and heart rate were measured throughout the stages. Subjects who received 30% oxygen recalled more words than those who received 21% oxygen, which shows 30% oxygen supply has influenced positively on memory cognitive performance. When 30% concentration oxygen is supplied, the blood oxygen saturation in the task phases was increased and the heart rate decreased when comparing to 21%. It means that 30% oxygen can stimulate brain activation by increasing actual blood oxygen concentration in the process of cognitive performance, and the heart rate decreases because enough oxygen is supplied to process the cognitive performance.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.43-51
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• 2024

The addition of oxygen scavengers to food products helps to reduce oxygen exposure, thereby mitigating deterioration, including changes in taste, odor, and color, as well as inhibiting microbial growth. Despite the advantages of the existing non-metallic oxygen removal materials in terms of safety for the human body and suitability for use in microwave ovens, their utilization has been limited due to their slow reaction initiation speed. Therefore, in the current study, sodium metabisulfite was impregnated into various porous media, including halloysite nanoclay, activated carbon, montmorillonite, and silica gel. The oxygen scavenger, produced by impregnating silica gel with sodium metabisulfite, demonstrated a 425% improvement in the initial oxygen removal rate compared to pure sodium metabisulfite. Additionally, sachets containing an oxygen-removing composition with an enhanced oxygen removal rate effectively decreased the oxygen concentration to less than 0.5% on the third day of storage in apple packaging, without elevating carbon dioxide levels. Moreover, it proved effective in preventing the browning of the apple surface. Therefore, the SM/SG oxygen-removal composition can be effectively applied to active food packaging by controlling the oxygen concentration within the packaging.

• Journal of Photoscience
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• v.9 no.2
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• pp.409-411
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• 2002

In order to prevent side reactions due to free radical formation occurring in the reactions of singlet oxygen generated in solution phse, it was required that singlet oxygen is generated in gas phase from an apparatus of a solid-gas system. We have accomplished to construct an apparatus generating singlet oxygen in solid-gas system, which is composed of a flexible optical fibre tube connected by a dye-sensitizer probe containing rose bengal dye on polymer or inorganic material. Through the optical fibre tube visible light from a laser and an oxygen stream are passed into the sensitizer probe where singlet oxygen is generated. The determination of singlet oxygen was carried out by two methods. One involves the detection of the luminescence of singlet oxygen at 1268 mn and the other involves the chemiluminescence reaction of a dihydroisobenzofuran with singlet oxygen emitting luminescence at 456 nm.