• Journal of Sensor Science and Technology
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• v.5 no.6
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• pp.7-14
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• 1996

In order to develop gas sensor operating at low temperature, thick film $Co_{3}O_{4}$ sensor was fabricated. $Co_{3}O_{4}$ powder was prepared by precipitation from cobalt nitrate solution and the powders containing ethylene glycol as a binder was screen-printed on alumina substrate. Characteristics of sensitivity, response time, and recovery were investigated in terms of binder content and heat treating conditions. The $Co_{3}O_{4}$ sensor contained 15% ethylene glycol and heat-treated at $300^{\circ}C$ for 24hr showed the highest sensitivity at the operating temperature of $250^{\circ}C$. Its sensitivity of 1.1 to 5000ppm butane gas was very high, as compared with $0.8{\sim}0.85$ at the operating temperature of $350{\sim}400^{\circ}C$ for a commercial $SnO_{2}$ gas sensor. It is found that response time was fast, but recovery was poor for the sensor.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.86-92
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• 2004

This research was carried out to examine the ethylene gas adsorption and preservation life of white charcoal boards for packaging. Two types of white charcoal board were made of #40-60 charcoal particles and mixed charcoal particles with PVA and MDI resin by wet process. For not only beauty effect but also avoiding stain from touching, white charcoal boards were overlaid with two kinds of overlay material, thin printed paper and non woven fabric. A charcoal board adsorbed ethylene gas much more than the paper and even white charcoal itself. There was no difference between two board types, between overlay treatments, and between overlay materials. Gray mold growth of strawberry arised after 2 days in a paper box and after 4 days in a white charcoal board. Preservation life of white charcoal board box was approximately twice more than that. of a paper box. There was no difference in the ability of keeping freshness between two board types, between overlay treatments, and between overlay materials.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.286-288
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• 2014

This study deals with the catalyst free radio frequency plasma assisted polymerization of ethylene glycol using nitrogen as reactive gas to modify the surface chemistry and morphology. The deposited film was characterized through various analysis techniques i.e. surface profilometry, Forier transform infrared spectroscopy, water contact angle and UV-visible spectroscopy to analyze film thickness, chemical structure, surface energy and optical properties respectively. The surface topography was analyzed by Atomic force microscopy. It was observed that the ethylene oxide behaviour and optical transmittance of the film were reduced with the introduction of nitrogen gas due to higher fragmentation of monomer. However the hydrophilic behavior of the film improved due to formation of new water loving functional groups suitable for biomedical applications.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.2
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• pp.97-101
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• 2017

Fruits are subjected to a variety of vibration stress during the transportation from a production area to markets. Vibration inputs are transmitted from the transporting vehicle through the packaged fruit. And the steady state vibration input may cause serious internal damage of fruit. Product quality of fruits declines by various factors while they are stored right after harvesting and among the substance in charge of post ripening action, ethylene ($C_2H_4$) biosynthesis increases fruits' respiration process after harvesting and decreases storage expectancy. Ethylene production of apples rapidly increases while storage duration becomes longer. This tendency is much clearer for the apples with vibration stress at input acceleration level. When there was no vibration stress, change in ethylene production level of apples are not very large during storage. Ethylene production rates inside the gas collecting container increased significantly ($p{\leq}0.05$) after 24 hours storage, particularly for apples with vibration stress ($0.7{\mu}l/kg{\cdot}hr$ (1st stack), $0.78{\mu}l/kg{\cdot}hr$ (2nd stack), $0.96{\mu}l/kg{\cdot}hr$ (3rd stack)); whereas less ethylene was produced in control apples ($0.18{\mu}l/kg{\cdot}hr$ during storage. Also ethylene production rates of apples according to the stack position were significantly different ($p{\leq}0.05$). The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased ethylene production.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.169-173
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• 1996

This experiment was conducted to investigate the effect of ethylene adsorbent removing ethylene gas produced from apple fruits in poly ethylene film bag storage. The treatment of ethylene adsorbent was not effected the change in soluble solids and organic acid content of fruits. The fruit softening was remarkably delayed by the absorbent treatment, and the more amount of it was the more effective. The ethylene evolution and respiration of fruits reduced or decreased by this treatment during storage. The ethylene adsorbent for 'Fuji' apple fruit was effective more than 30g per 10kg fruits.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.93-100
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• 2002

For natural gas and LPG fuel, measurements on the concentrations of individual exhaust hydrocarbon species have been made as a function of air-fuel ratio in a 2-liter four-cylinder engine using a gas chromatography. NMHC in addition to the species of HC, other emissions such as CO$_2$, CO and NOx were examined for natural gas and LPG at 1800rpm far two compression ratios (8.6 and 10.6). Fuel conversion efficiencies were also investigated together with emissions to study the effect of engine parameters on the combustion performances in gas engines especially under the lean bum conditions. It was found that CO$_2$ emission decreased with smaller C value of fuel, leaner mixture strength and the higher compression ratio. HC emissions from LPG engine consisted primarily of propane (larger 60%), ethylene and propylene, while main emissions from natural gas were mothane (larger than 60%), ethane, ethylene and propane on the average. The natural gas was proved to give the less ozone formation than LPG fuel. This was accomplished by reducing the emissions of propylene, which has relatively high MIR factor, and propane that originally has large portion of LPG. In addition, natural gas shows a benefit in other emissions (i.e. NMHC,NOx, CO$_2$and CO), SR and BSR values except fuel conversion efficiency.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2069-2071
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• 2005

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.301-305
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• 2010

Cutting procedures where qualities are determined by various demand factors largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay for post shipbuilding stages such as in welding and assemblage lines which could become factors for reduced economic viability of the project. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component and these methods applied particularly to ship plate cutting gives relatively slow cutting speed and generates large quantities of harmful and sometimes poisonous polluting fumes of which warrants an urgent need to look for alternative cutting methods. Recent introduction of hydrox gas generated by electrically dissociating water into hydrogen and oxygen components to be utilize as an alternative cutting fuel has resulted not just in visible improvement on cutting quality and speed over the existing methods but it has also been welcomed as an environmentally friendly clean fuel source. This paper has been prepared to serve as the basis for accommodating this environmentally friendly hydrox gas cutting method into actual working environment by observing and recording hydrox gas cutting thermal characteristics.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.2
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• pp.141-150
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• 2014

Purpose: This was a study on the expiration date of Ethylene Oxide (EO) gas sterilization and effects of the environmental factors of temperature, humidity and type of cabinet in sterile goods storage area on the expiration date. Methods: Sterile goods storage areas from 13 departments in one hospital were selected and 455 EO gas sterilization samples were prepared and kept in those areas over the 14 months of the study. Each sample was tested with a microbiological culture in the laboratory every week. If the result was positive, the sample was regarded as contaminated. The researcher visited once a month to check the temperature, humidity and type of cabinet. Results: With the exception of 1 sample which was positive at 56th week. 454 samples were confirmed as negative. The environment of the samples storage area was measured monthly. The annual average temperature was $24.2{\pm}1.6^{\circ}C$, and the mean relative humidity $34.7{\pm}15.2%$. The types of cabinet were 7 open and 6 closed. Conclusion: The results of the microbiological culture at 13 months showed that none of the samples were contaminated. Therefore the hospital's existing Expiration Date can be extended from 6 months to 13~14 months.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.1
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• pp.17-21
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• 1997

Zeolite powder used by molecular sieve, adsorbants and catalist. 1N HCl teated zeolite powders for freshness extension of fruits and vegetables showed that specific surface area was $300.29m^2/g$ largest then that of the others, and ethylene gas adsorbability was 29.07 cc/g. And then 0.5N NaCl Henting after 1N HCl treated zeolite powder showed that specific surface area and ethylene gas adsorbability was $329.43m^2/g$ and 35.64 cc/g largest then those of the others. Specific surface area of processed zeolite powder treated by high intensity magnetic seperator(HIMS) showed $369.67m^2.g$, ethylene gas adsorbability was 39.87cc/g. In this study, it could be employ 0.5N NaCl treat and HIMS methods as MA packaging materials for freshess extension of fruits and vegetables.