• Title/Summary/Keyword: Ethylene gas

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Low temperature-operating NiO-CoO butane gas sensors

  • Jung, Dong-Ho;Choi, Soon-Don;Min, Bong-Ki
    • Journal of Sensor Science and Technology
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    • v.17 no.4
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    • pp.303-307
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    • 2008
  • $NiO,\;Cu_2O,\;Mn_2O_3$ and $Cr_2O_3$ as p-type semiconductors were added in CoO with 15 wt.% ethylene glycol binder and measured the butane gas sensing characteristics. The highest sensitivity is obtained for the NiO-CoO sensors. CoO-20 at.% NiO sensor with 15 wt.% ethylene glycol binder sintered at $1100^{\circ}C$ for 24 h exhibits high sensitivity of 90 % to 5000 ppm butane gas at the sensor temperature of $250^{\circ}C$, compared to low sensitivities at the low operating temperature for commercial sensors. Response and recovery times are, respectively, within few seconds and 1min in the static flow system, indicating rapid adsorption and desorption of butane gas on sensor surface even at this low temperature.

Impact of mixer design to reactants mixing characteristics and gas-phase reactions in the mixing region of a hydrocarbon reformer (개질기 혼합영역 형상에 따른 반응물의 혼합도 및 가스상 반응특성에 대한 수치해석적 연구)

  • Kim, Sunyoung;Bae, Joongmyeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.99.1-99.1
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    • 2011
  • Reactant mixing has a critical role in ensuring reformate quality and an important design objective is to achieve sufficiently complete mixture of reactants. For that purpose it is required to understand the coupled transport-kinetics phenomena in the mixing region. Three-dimensional computational fluid dynamics model was developed and validated in previous works. The mixing characteristics in various alternatives of a prototype mixing chamber were compared, and then a reduced reaction kinetics was applied to two extreme designs for investigating the impact of gas-phase reactions. Both designs did not reach threshold ethylene mole fraction of 0.001, but surprisingly more ethylene was generated in the design having better mixing characteristics. The presentation will deliver the development process of coupled transport and kinetics model briefly and the detailed information about the mixing characteristics and gas-phase reactions in two mixer designs.

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Effect of nitrogen doping on properties of plasma polymerized poly (ethylene glycol) film

  • Javid, Amjed;Long, Wen;Lee, Joon S.;Kim, Jay B.;Sahu, B.B.;Jin, Su B.;Han, Jeon G.
    • 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.

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Ethylene Production of Packaged Apples under Vibration Stress in Simulated Transportation Environment

  • Jung, Hyun-Mo;You, Young-Ok
    • 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.

Effect of Ethylene Adsorbent on Apple Fruit Quality during Storage (사과과실 저장성에 미치는 에틸렌흡착제의 효과)

  • Ahn, Young-Jik;Choi, Jong-Seung;Min, Byung-Hoon;Yi, Kyoung-UK
    • 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.

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Emission Characteristics of a Gas Fueled Sl Engine under Lean Burn Conditions (가스연료엔진의 희박영역에서의 배출가스특성에 관한 연구)

  • 김창업;배충식
    • 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.

A Study on the Thermal Characteristics of LPG and Hydrox Gas Cutting (Hydrox Gas 절단과 LPG 절단의 열적특성에 관한 연구)

  • Kim, Hong-Gun;Kwac, Lee-Ku
    • 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.

A Study on Expiration Date on Ethylene Oxide Gas Sterilization Products - Related to Storage Environment - (Ethylene Oxide 가스 멸균물품의 유효기간에 관한 연구 - 보관환경을 중심으로 -)

  • Son, Jeong Sook;Yu, Il Kyong
    • 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.

Development of MA Packaging Materials for Freshness Extension of Fruits and Vegetables(2) (과실 채소류의 MA포장용 소재의 효과제고에 관한 연구(2))

  • Park, Hyung-Woo;Park, Jong-Dae;Kim, Byung-Sam;Kim, Hoon;Yang, Han-Chul
    • 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.

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