• Fire Science and Engineering
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• v.22 no.2
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• pp.57-62
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• 2008

Most of all the Korean home use a wallpaper as a decoration and finishing of interior. One of the fire spread factor in a house is a combustion of wall paper. There were some research concerning oxygen index in a ambient temperature. The purpose of this study is to investigate the difference of oxygen index of a wallpaper between ambient and high temperature and a effect on the fire spreading. Based on the result, the difference of oxygen index between ambient temperature and high temperature showed $5{\sim}8%$. Difference of 0.1% of oxygen index show big differences in combustion length of sample. Therefore, it was found that the decrease of oxygen index at elevated temperature is a important factor in fire spread.

• Fire Science and Engineering
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• v.32 no.5
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• pp.1-5
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• 2018

Curtains are used for shading in windows. Since most curtains are made of flammable materials and are installed vertically, curtains can be an important factor in fire spreading. Accordingly, it is important to predict fire behaviors in studies on the combustion characteristics of flammable interior decorations, such as curtains. In this study, to analyze the combustion characteristics of six kinds of curtains, which are widely used interior decorations, the oxygen index was measured at room temperature and higher temperature. As a result of the experiment, the oxygen index at higher temperature of all specimens was about 3%~7.5% lower than that at room temperature and difference of 0.2% of oxygen index show big differences in combustion phenomenon of specimens. Therefore, when flame retardancy is evaluated with the oxygen index value of flammable interior decorations, the oxygen index value at higher temperature should be sufficiently considered.

• Journal of the Korean Society of Combustion
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• v.8 no.2
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• pp.1-6
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• 2003

Numerical simulations are conducted at atmospheric pressure in order to understand the effect of the oxygen enrichment level on structure of $CH_4/O_2/N_2$ premixed flames. Under several equivalence ratios the flame speeds are calculated and compared with those obtained from the experiments, the results of which are in good agreement. The effects of the oxygen enrichment are investigated on flames under fuel-rich conditions. As the oxygen enrichment level is increased from 0.21 to 1, the flame speed and the temperature are increased. The emission index of $CO_2$ is decreased in cases of flames for fuel rich mixtures, so the efficiency of combustion may be decreased. The maximum emission index of NO is obtained for 0.6 of the oxygen enrichment level.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.690-693
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• 2003

An Si substrate (100) was oxidized at $400^{\circ}C$ in inductively coupled oxygen plasma. Interstitial oxygen was found in the Si substrate at the initial stage of oxidation by IR measurements. An x-ray rocking curve of Si substrates showed a lower peak intensity due to lattice distortion by the interstitial oxygen. The refractive index of thin oxides, below which interstitial oxygen existed in the Si substrate, was smaller than the refractive index of thick oxides, below which no interstitial oxygen existed. The interstitial oxygen was found by plasma oxidation using $O_{2}$ gas and $N_{2}O$ gas. The inductively coupled plasma oxidation using $N_{2}O$ gas was performed by atomic oxygen, not by molecular oxygen, indicating that atomic oxygen in plasma is responsible for the incorporation of interstitial oxygen.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.174-179
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• 2006

In this study, we compared Oxygen Index by ISO 4589-2 with Fire Spread by ISO 5658-2. The result shows that the tset values of Fire Spread such as IT, CFE, Qsb have mutual relations with thoses of Oxygen Index values in some samples. And we found that the tset values of Fire Spread make up for the insufficient points of Oxygen Index has its limits to evaluate the properties of fire for the interior materials of the railroad vehicles.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.396-400
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• 1989

The oxygen index test was carried out to obtain the relative flammability of wood-based materials (plywood, MDF, particleboard) and their oxygen indices. The oxygen index is the minimum concentration of oxygen, expressed as volume percent, in a mixture of oxygen and nitrogen that will just support flaming combustion of a material under the specified laboratory conditions. In this study the oxygen indices were calculated by using the Dixon and Massey's Up and Down method("N" Large method). The obtained results were as follows : 1. The oxygen indices calculated with Up and Down method were 27.9% for plywood, 26.9% for MDF, and 26.2% for particleboard, indicative of plywood being more difficult to burn than MDF and particleboard Lender the same surrounding conditions. 2. The oxygen indices were not affected by the total gas flow rate.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.255-259
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• 1990

To investigate relative flammability in flaming combustion among 10 softwoods and 10 hardwoods, oxygen indices were determined for flat-grained sapwoods through Up and Down method following oxygen index test of ASTM D 2863-77. Oxygen index ranged from 21.0 for Pinus strobus to 28.2 for Larix gmelinii var. principis-ruprechtii in softwoods and from 20.7 for Populus davidiana to 27.6 for Quercus acntissima in hardwoods, which indicates Larix gmelinii var. principis-ruprechtii and Quercus acutissima being ranked first in inflammability and Pinus strobus and Populus davidiana being the least in fire resistance by softwood and hardwood because highly flammable materials are likely to have a low oxygen index.

• Journal of Korean Academy of Nursing
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• v.53 no.4
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• pp.468-479
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• 2023

Purpose: This study aimed to evaluate the use of the respiratory rate oxygenation (ROX) index, ROX-heart rate (ROX-HR) index, and saturation of percutaneous oxygen/fraction of inspired oxygen ratio (SF ratio) to predict weaning from high-flow nasal cannula (HFNC) in patients with respiratory distress in a pediatric intensive care unit. Methods: A total of 107 children admitted to the pediatric intensive care unit were enrolled in the study between January 1, 2017, and December 31, 2021. Data on clinical and personal information, ROX index, ROX-HR index, and SF ratio were collected from nursing records. The data were analyzed using an independent t-test, χ² test, Mann-Whitney U test, and area under the curve (AUC). Results: Seventy-five (70.1%) patients were successfully weaned from HFNC, while 32 (29.9%) failed. Considering specificity and sensitivity, the optimal cut off points for predicting treatment success and failure of HFNC oxygen therapy were 6.88 and 10.16 (ROX index), 5.23 and 8.61 (ROX-HR index), and 198.75 and 353.15 (SF ratio), respectively. The measurement of time showed that the most significant AUC was 1 hour before HFNC interruption. Conclusion: The ROX index, ROX-HR index, and SF ratio appear to be promising tools for the early prediction of treatment success or failure in patients initiated on HFNC for acute hypoxemic respiratory failure. Nurses caring for critically ill pediatric patients should closely observe and periodically check their breathing patterns. It is important to continuously monitor three indexes to ensure that ventilation assistance therapy is started at the right time.

• Fire Science and Engineering
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• v.24 no.1
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• pp.122-127
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• 2010

The combustion characteristics of phenol foam were analysed using variable external irradiation level (20, 25, 35, 50, and $70kW/m^2$) and in the mixture gas of oxygen/nitrogen. The oxygen index were carried out from the oxygen index tester (KS M ISO 4589-2) and ignition time, critical heat flux, and mass loss rate were carried out from the mass loss calorimeter (ISO 5660-1). As the results of this study, the critical heat flux and average mass loss rate were $28.99kW/m^2$ and $0.56{\sim}1.77g/m^2s$ respectively at the variable external irradiation level. And the limited oxygen index were 45.1% in mixture gas of oxygen/nitrogen. In conclusion, we knew that phenol foam had the best performance than other foam materials in fire safety from all data of this study.