• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.596-603
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• 2009

This study aimed to examine the influence of adding an oxygen vector, n-dodecane, on hyaluronic acid (HA) production by batch culture of Streptococcus zooepidemicus. Owing to the high viscosity of culture broth, microbial HA production during 8-16 h was limited by the oxygen transfer coefficient $K_La$, which could be enhanced by adding n-dodecane. With the addition of n-dodecane to the culture medium to a final concentration of 5% (v/v), the average value of $K_La$ during 8-16 h was increased to $36{\pm}2h^{-1}$, which was 3.6 times that of the control without n-dodecane addition. With the increased $K_La$ and dissolved oxygen (DO) by adding 5% (v/v) of n-dodecane, a 30% increase of HA production was observed compared with the control. Furthermore, the comparison of the oxygen mass transfer in the absence and presence of n-dodecane was conducted with two proposed mathematical models. The use of n-dodecane as an oxygen vector, as described in this paper, provides an efficient alternative for the optimization of other aerobic biopolymer productions, where $K_La$ is usually a limiting factor.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.256-260
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• 2003

A computer program to calculate thermodynamic properties of oxygen is developed. Procedures for the calculation is briefly discussed. The program calculates unknown thermodynamic properties fixing the state with two independent input properties. If input value by user is inappropriate, it displays an error message. In addition user can change units with easy. The program developed in this work can be utilized to calculate parameters required for the simulation and design of an equipment using oxygen.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.369-373
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• 2002

The liquid phase oxidation of p-xylene has been carried out with oxygen-enriched gas, and the manganese component was precipitated probably via over-oxidation to $Mn^{4+}$. The precipitation increased with rising oxygen concentration in the reaction gas and occurred mainly in the later part of the oxidation. The activity of the reaction decreased, and the blackening of the product and side reactions to carbon dioxide increased with the degree of precipitation. Precipitation can be decreased with the addition of metal ions, such as cerium, chromium and iron.

• 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.

• 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.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.240-244
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• 2003

A novel integrated method for increasing dissolved oxygen concentration in culture media has been developed. It involves adding hydrogen peroxide to the medium, which is then decomposed to oxygen and water by catalase and adding vegetable oil to the medium as antifoam agent and oxygen vector. A new apparatus for automated addition of hydrogen peroxide to the bioreactor to keep the dissolved oxygen concentration constant over the range $10-100%\;{\pm}\;5%$ was tested. A significant increase (over threefold) of cultivation time was obtained while the dissolved oxygen concentration remained stable ($30%\;{\pm}\;5%$). Therefore, use of corn oil mixed with Ca-stearate as oxygen vector and antifoam and hydrogen peroxide as oxygen source to control excessive foam that was generated by microorganism biosurfactant, GB16-BS produced at Bacillus sp. GB16 cultivation was appropriate for stable cultivation.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.101-112
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• 2000

An Experimental study of oxygen enriched double inversed diffusion flame was conducted to understand the flame characteristics and radiation heat transfer. The infrared radiation meter was used to measure of various combination of fuel, air and pure oxygen. The results show that oxygen enriched double inversed diffusion flame is very effective to increase of thermal radiation and proper addition of pure oxygen in air flow can intensity thermal radiation of flame. And it can be found that oxygen enriched double inversed diffusion flame could give benefits of cost effective and very high energy saving.

• Journal of the Korean Society of Combustion
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• v.6 no.2
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• pp.50-64
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• 2001

An experimental study of oxygen enriched double inversed diffusion flame was conducted to understand the flame characteristics and radiation heat transfer. The infrared radiation meter was used to measure of various combination of fuel, air and pure oxygen. The results show that oxygen enriched double inversed diffusion flame is very effective to increase of thermal radiation and proper addition of pure oxygen in air flow can intensify thermal radiation of flame. And it can be found that oxygen enriched double inversed diffusion flame could give benefits of cost effective and very high energy.

• Microbiology and Biotechnology Letters
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• v.28 no.5
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• pp.298-302
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• 2000

Fermentation parameters were estimated by use of a vent gas analyzer coupled to a computer data acquisition system in cultivation of Phellinus linteus WI-001, pro-ducer of polysaccharides known to have potent anticancer activities. Oxygen uptake rate(OUR), a critical indicator of the cells activities, was calculated by applying oxygen mass balance. In addition, by dividing the oxygen uptake rate hy the total oxygen consumed, on-line estimation of the cells specific growth rate was successfully done. It was also possible to estimate cell concentration directly bt use of oxygen-cell yield($Y_{x/o}$ ) which was obtained based on a correlation between cell growth and total oxygen consumed.

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.49-53
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• 2009

The oxygen barrier films were formed on poly(ethylene terephthalate) (PET) substrate by a sol-gel process using 3-aminoproprytrimethoxysilane (APTMOS). The effects of solvent type, coating times and incorporation of fumed silica on oxygen permeability coefficient were investigated. The APTMOS coating film prepared from methanol as a solvent exhibited higher oxygen barrier properties than that using THF. The oxygen permeability coefficient of coated film with APTMOS/methanol by coating 7 times was measured to be $2.28{\times}10^{-6}$, while that of PET film was $1.16{\times}10^{-4}$ GPU. The addition of fumed silica does not affect the oxygen barrier properties. It may be explained that silica particles disrupt chain packing, which leads to an increase in free volume for permeation.