• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.231-232
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• 2002

대기 중 휘발성유기화합은 오존생성의 전구물질 및 유해화학물질 그리고 일부는 악취물질로 작용하는 주요 대기오염물질로 주목받고 있으며, 여러 가지 VOCs의 배출원 중에서 세탁소도 주요 발생원중 하나로 주목받고 있다. 세탁에 사용되는 유기용제에는 퍼클로로에틸렌(PCE)과 불소계용제, 석유계 용제가 있는데 일본을 제외한 외국에서는 밀폐형기계인 PCE를 사용하고 있는데 반해, 우리나라에서는 약 95% 정도의 세탁소가 석유계 용제를 사용하고 있다. (중략)

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.2
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• pp.59-63
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• 2014

The quality changes of 'Fuyu' persimmon fruits chill-injured on tree with different time periods were evaluated during storage of 6 weeks at $0^{\circ}C$. There was no significant difference among treatments in the weight loss, which increased with storage time. Firmness was found to be very important factor determining the quality level of persimmon fruit during the storage. The increased chill-injured period decreased the firmness, indicating the rapid fruit softening. While the firmness of the persimmons not exposed to chill-injured condition was not changed significantly during the storage period, the firmness of persimmon fruits chill-injured for 1, 3, and 5 days decreased from 26.7, 16.1, 10.8 N to 18.2, 12.22, and 5.8 N for 6 weeks. The total solids content and total acidity did not significantly change during the storage period. The amount of ethylene production from the chill-injured fruits was almost 2 times higher than that without low temperature injury. The results indicated that persimmon fruit injured by low temperature exposure directly affected to the changes of its ethylene production and firmness during storage.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.260-266
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• 2006

For the synthesis of polyurethane memory foam stabilizer with fine cells, hydrosilylation reaction with various polyalkyleneoxides and hydrogen functional group of polymethylhydrogensiloxane (D = 75, D' = 15) was conducted. Polyalkyleneoxides (PAO) used in this research were ethylene oxides or ethylene-co-propylene oxides with terminal groups of hydroxides or methyl groups. To analyze the molecular structures and molecular weights as well as the reaction yields (98%), NMR and GPC analysis were executed. Synthesized siloxane surfactants modified with polyalkylene (EO = 12 units) were applied to producing flexible polyurethane fine memory foams from 0.6 pphp to 2.0 pphp. By controlling the amount of the surfactant, physical characteristics, the polyurethane memory foam with cell size (minimum $0.868{\mu}m$), air flows (-78 KPa), and recovery times (8 sec) were achieved.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.190-195
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• 1999

The thermal pyrolysis of chlorodifluoromethane (R22) for producting tetrafluoroethylene (TFE) has been studied using the tubular reactor designed by the authors. The reaction temperature over $600{\sim}850^{\circ}C$, residence time over 0.005~0.6 sec, and steam/R22 ratio 3 to 30 were varied through experiments to analyze the effect of these variables on the conversion of R22 and selectivity for TFE. We have provided the guidelines for the optimal operation and design for the pyrolysis reactor. With increasing the dilution ratio, not only the conversion of R22 but also the selectivity for TFE increase. The optimum range of reaction temperature was $700{\sim}750^{\circ}C$ and the residence time 0.07~0.1 sec. In the kinetic study, first order rate equation was fitted well with the experimental data. This indicates that the main reaction step is a $CF_2$ generation from R22 pyrolysis. The range of activation energy for the rate constant was obtained 44.7~48 kcal/mol.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1882-1888
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• 2008

Effects of 1-MCP(1-methylcyclopropene) on the postharvest life and fruit quality of cucumber 'Baekdadaki' were investigated. Cucumber were held at room and cold chamber($10^{\circ}C$) treated with several concentrations of 1-MCP. Physico-chemical characteristics such as fresh weight and firmness were greatly varied during storage, and the treatment with I-MCP(500ppb) showed the minimal loss of the values at harvest. The peel b value representing a senescence process was higher investigated in 1-MCP(250 and 1,000ppb treatment, and led to the apparent yellowing and softening after cold storage for 15 days. 1-MCP(500ppb) showed lower decay rate and better marketability of cucumber than other treatments after cold storage for 15 days. The respiration rate was higher found in cucumber treated with 1-MCP(250ppb) than in other treatment. Ethylene evolution was most detected in cucumber treated with 1-MCP(1000ppb) after room storage for 6 days. 1-MCP did not affect the production of ethylene in cucumber during room and cold storage.

• Journal of Plant Biology
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• v.38 no.3
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• pp.235-242
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• 1995

Effects of methyl jasmonate (MeJA) on ethylene production in tomato(Lycopersicon esculentum Mill.) hypocotyl segments and fruits were studied. Ethylene production in tomato hypocotyl segments was inhibited by the increasing concentratons of MeJA, and 450 $\mu$M of MeJA showed 50% inhibitory effect. Time course data indicate that this inhibitory effect of MeJA appeared after 3 h of incubation period and continued until 24 h. Inhibition of ethylene producton by MeJA was due to the decrease in 1-aminocyclopropane-1-carboxylic acid(ACC) synthase activity. However, MeJA treatment had no effect on ACC oxidase activity and the accumulaton of ACC oxidase mRNAs. MeJA also inhibited auxin-induced ethylene production by decreasing in ACC synthase activity. In contrast, MeJA stimulated ethylene production in tomato fruits. When 30 $\mu$L/mL MeJA was treated in a gaseous state, ethylene production doubled and this stimulating effect continued until 4 days. To investigate the mechanisms of MeJA on ethylene production, ACC synthase and ACC oxidase activities were examined after MeJA treatment. MeJA increased the activities of both ACC synthase and ACC oxidase, and induced ACC oxidase mRNA accumulation. These data suggest that MeJA plays distinct roles in the ethylene production in different tomato tissues. It is possible that MeJA affects differently the mechanisms of signal transuction leading to the ethylene biosynthesis.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.2
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• pp.179-185
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• 2013

The behavior of surface film formation was greatly dependent on the speed of potential cycling. In $LiClO_4$ / EC + DEC, cyclic voltammetry results showed that the peaks originated from surface film formation on graphite electrode at the high charge-discharge rate was shifted to the lower potentials as the charge-discharge rate decrease. This indicates that surface films with different morphology and thickness were formed by different charge-discharge rate. Transmission electron microscopy (TEM) results indicated that the properties such as thickness and morphology of the surface film were greatly affected by the charge-discharge rate. Electrochemical impedance spectroscopy (EIS) showed that the resistance of surface film was affected by the speed of potential cycling. In addition, the charge transfer resistance was also dependent on the charge-discharge rate indicating that the charge transfer reaction was affected by the nature of surface film. TEM and EIS results suggested that the chemical property as well as the physical property of the surface film was affected by the charge-discharge rate.

• Journal of the Korean Chemical Society
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• v.28 no.2
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• pp.109-113
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• 1984

The effects of various supports on the activity and the selectivity for the ethylene oxidation was investigated over$ Ag/{\alpha}-Al_2O_3$ and $Ag/SnO_2$ by Auger, EPR spectroscopy and reaction studies. The results indicate that over $Ag/SnO_2$ catalyst O- chemisorbed on $SnO_2 $participates in the complete oxidation of ethylene lowering the selectivity for the formation of ethylene oxide.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.71-75
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• 2010

This study is experimented to observe an influence of experimental conditions on production characteristics of slurry ice by injection operating water to cooling plate. And at this experiment it used ethylene glycol-water solution and the concentration is 10 to 20wt%. The experimental apparatus was constructed of ethylene glycol-water solution and slurry ice storage tank, brine tank, pumps for ethylene glycol-water solution and brine circulating, a mass flow-meter, data logger for fluid temperature measuring and a vertical circular tube with single copper plate as test section. The experiments were carried out under various conditions, with mean velocity of fluid at the entry ranging from 1.0 to 2.0m/s and the cooling temperature of $-17^{\circ}C$ to $-10^{\circ}C$.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.94-100
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• 1998

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by a microwave plasma. The yield of C2+ product could be increased from 29.2% to 42.2% with increasing plasma power(40~120 watt) and decreasing flow rate(40~5 mL/min) of methane. With catalyst, the selectivities of ethylene and increased while yield of C2+ remaining constant. Among various catalysts, Fe catalyst showed the highest ethylene selectivity of 30%. A natural gas could produce more C2+ than a pure methane. This is due to high reactivity of ethane and propane in the natural gas.