• Journal of ILASS-Korea
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• v.15 no.3
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• pp.109-114
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• 2010

The implementation of gelled propellants systems offers high performance, energy management of liquid propulsion, storability, and high density impulse of solid propulsion. The present study focused on the macroscopic spray characteristics of liquid sheets formed by triplet impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are compared to experiments conducted on spray images which formed by triplet impinging jets concerning with airassist effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure and high pressure, closed rim pattern shape appeared by polymeric effect from molecular force and showed inactive atomization characteristics, because of extensional viscosity related by restriction of atomization process and breakup time delay of turbulence transition. As increasing mass flow rate of the air(increasing GAR), spray breakup level is also increased.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.74-81
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• 2016

Space propulsion system produces required thrust for satellites and space launch vehicles by using chemical reactions of a liquid fuel and a liquid oxidizer typically. Among several liquid propellants, the monomethylhydrazine-dinitrogen tetroxide is expecially preferred for a GEO satellite propellants due to their better storability in liquid phase during a long mission life under a freezing space environment. Recently, a development of the monomethylhydrazine-dinitrogen tetroxide bipropellant system becomes important as the national space program requires the heavier and the more efficient space system. Thus, the objective of the present study is to review a foreign research trend of a chemical reaction between the monomethyhydrazine fuel and the dinitrogen tetroxide oxidizer to understand a fundamental basis of their characteristics to prepare for domestic development in future.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.14 no.1
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• pp.31-33
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• 2008

The effects of packaging conditions on freshness extension of green pepper were investigated during 30days of storage at $10^{\circ}C$ and $18^{\circ}C$ Corrugated cardboard and EPS box used as packaging materials. The rate of weigh loss, vitamin C and chlorophyll contents, and hunter color of green paper were changed last significantly in the samples stored in the EPS box at low temperature storage condition($10^{\circ}C$) among treatments. The combination of EPS box and low temperature was the most effective treatment to extend the storability of green pepper.

• Food Science and Preservation
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• v.7 no.1
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• pp.19-22
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• 2000

This study was carried out investigate the storability of onions on calcium spraying, after cutting foliage, 6 different treatemnt , the dilution spraying of calcium nitrate 9 3%, 6%) , calcium carbonate(3%, 6%), dust scattering and the controls were evaluated for rotting, sprouting, healthy bulb and total weight loss ratio during storage. Rotting ratio on the dilution spraying of 6% calcium carbonate was lower than that of the control after 4 months storage by 16.7%. Sprouting and total weight loss were decreased in the dilution spraying of 6% calcium carbonate.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.277-283
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• 2011

The goal of this study was to make more efficient use of Ligularia fischeri which has both medical and cooking applications after freezing and drying. We manufactured Sulgidduk containing 0, 2, 4, 6 and 8% of Ligularia fischeri powder. Chemical analysis showed that Ligularia fischeri powder contained, 5.77% water, 19.97% crude protein, 1.89% crude fat, 13.12% crude ash, and 9.73% crude fiber. The water content of Sulgidduk to which Ligularia fischeri was added ranged from 37.72~40.20%. As more Ligularia fischeri was added, the L value and 'a' value increased, while the 'b' value did not significantly change. Optimal preference was for a 4% content of added Ligularia fischeri powder. Based on the results of this experiment, Sulgidduk manufactured with added Ligularia fischeri powder showed less hardness than the control group throughout a period of storage, and adequate addition of Ligularia fischeri powder can effectively enhance the storability of Sulgidduk containing Ligularia fischeri.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.85-89
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• 2018

The effects of distribution temperature due to season all changes on quality and storability of baby leaf beet (Beta vulgaris L.) was examined in modified atmosphere (MA) packages. The beet leaf had been harvested at the 10 cm leaf length stage and packaged with an oxygen transmission rate (OTR) film of $1,300cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ and then held at 4 different distribution temperatures which were $-2^{\circ}C$, $4^{\circ}C$, $20^{\circ}C$, or $30^{\circ}C$ for 5 hrs and then stored for 18 days at $8^{\circ}C$. The loss of fresh weight of packged baby leaf beet was lowest at the $4^{\circ}C$ treatment, and below 0.6% in all distribution temperature treatments. The atmosphere composition in packages did not show any significant differences among treatments. The oxygen conc. was the highest at 18.0% after the $4^{\circ}C$ treatment, carbon dioxide conc. showed the maximum value of 4% at the $30^{\circ}C$ and $-2^{\circ}C$ treatments, and ethylene conc. was highest at the $10^{\circ}C$ treatment after 10 days in storage. The hardness was the highest at the $4^{\circ}C$ treatment on the final storage day. The $4^{\circ}C$ treatment showed the highest visual quality and the lowest off-odor and aerobic plate count. Therefore, it is necessary to establish a low-temperature distribution system which is controlled under $4^{\circ}C$, because the baby leaf beet's storability and microbial growth are effected even during a short time of 5 hrs during the distribution process.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.221-226
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• 2011

The study was carried out to investigate the effect of MA packaging materials on quality and storability of tomato in long distance export condition. We found that the fresh weight loss in perforated film was higher than other breathable films. The fresh weight of tomato (cv 'Madison') packaged with breathable films, such as 5,000 cc, 10,000 cc, $20,000cc/m^2{\cdot}day{\cdot}atm$ oxygen permeable films, reduced less than 0.6%, but perforated film that already being used for packaging horticultural crops showed 1.4% fresh weight loss during $5^{\circ}C$ storage for 20 days and then $20^{\circ}C$ storage for last 5 days with 85% relative humidity. The carbon dioxide and oxygen concentration in tomato packages showed proper level for MA storage in $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ breathable film treatment at $5^{\circ}C$ storage. Although at $20^{\circ}C$ storage, the carbon dioxide concentration increased sharply, the oxygen concentration decreased remarkably, the change of these gases concentration was the lowest in 20,000 cc film treatment. The ethylene concentration was sharply increased at $20^{\circ}C$ from $21^{st}$ day to $25^{th}$ day after $5^{\circ}C$ storage for 20 day, and the concentration was lower in 20,000 cc film treatment among the breathable film treatments. Until 20 days, at $5^{\circ}C$ storage all treatments did not exceed the marketability. However, the last 5 days during at $20^{\circ}C$, the fruit appeared fungal rots and the quality rapidly decreased. The $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ permeability treated tomato performed higher firmness (9.56 N), vitamin C (16.31 mg/100 gFW), and soluble solids ($7^{\circ}Brix$) than other breathable films at final storage day. The results suggest that the $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ permeable film treatment of tomato (cv 'Madison') performed the highest quality and storability of tomato for long distance exporting.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.109-116
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• 2010

Chicons are kinds of sprout vegetables which forced from the roots of chicory (Cichorium intybus L.). Experiments were performed to investigate the proper cultivation period and region of chicories which are 3 different cultivars for improving storability of chicon. The fresh weight of chicon packed with 20 ${\mu}m$ LDPE film decreased less than 0.5% during the storage at $10^{\circ}C$ in all treatments, and Chuncheon region treatment and 'Focus' cultivar treatment showed higher fresh weight loss than the others. And it decreased higher, as the cultivation periods was longer. The oxygen content in film was from 8% to 17% during storage at $10^{\circ}C$. There was not any significantly different oxygen content among cultivar treatments and cultivation region treatments, but 100 days' cultivation period treatment showed the highest content than the others. The carbon dioxide content in film showed around 3% during storage at $10^{\circ}C$. It also did not influenced by cultivars and cultivation regions, but 100 days' cultivation period treatment showed the lowest content than the others. The ethylene content in film was changed dramatically from 2 to 14 ${\mu}l{\cdot}l^{-1}$, and it showed around 8 ${\mu}l{\cdot}l^{-1}$ as approaching to 21 days after storage at $10^{\circ}C$. The visual quality of chicon deteriorated below marketability level from 12 days after storage at $10^{\circ}C$, and that of 'Metafora' cultivars decreased the highest. That of Pyeongchang region treatment was kept higher, and 'Vintor' cultivar treatment showed highest visual quality than the others which were grown in Pyeongchang region. The firmness of chicon increased, as the cultivation period was longer regardless of cutlivars and cultivation regions. The russet spotting that is ethylene injury symptom of chicon appeared at the latter term of storage and was higher in Chuncheon region treatment. Conculsionally, chicory that is for producing chicon should be grown more than 120 days in Kangwon region and grown in high-land region like Pyeongchang to improve the storability of chicon.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.116-122
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• 2014

This study was conducted to find out the appropriate packaging materials to extend the storability and maintain the quality of cherry tomato for modified atmosphere (MA) storage. Tomatoes were grown by hydroponic at a plastic house in Gangwon Province. Light red maturity stage tomatoes were harvested and packed with MA condition (10,000; 20,000; 40,000; 60,000; 80,000; and $100,000cc/m^2.day.atm$ $O_2$ permeability film) and perforated film to store at $5^{\circ}C$, $11^{\circ}C$ and $24^{\circ}C$. The fresh weight loss was less than 0.6% in all non-perforated breathable films at $^5{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$, but perforated film had less than 2.93% at $5^{\circ}C$, 13.29% at $11^{\circ}C$ and 27.24% at $24^{\circ}C$. The 20,000cc at $5^{\circ}C$ and $11^{\circ}C$, and the 40,000cc film at $24^{\circ}C$ balanced optimum carbon dioxide and oxygen concentration in the package to maintain quality. The 10,000cc film was appeared the significantly highest ethylene concentration at $5^{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$, this film had the lowest $O_2$ permeability. Visual quality, firmness, and soluble solids were maintained in 20,000cc films both at $5^{\circ}C$ and $11^{\circ}C$, the 40,000cc film at $24^{\circ}C$. There was no any trend in titratable acidity and vitamin C content of treated packed film types and temperatures at cherry tomatoes packages. Therefore, the appropriate MA condition for $5^{\circ}C$ and $11^{\circ}C$ is $20,000cc/m^2.day.atm$ $O_2$ permeability film; for $24^{\circ}C$ it is $40,000cc/m^2.day.atm$ $O_2$ permeability film because those films extended the storability through the firmness, soluble solids as well as visual quality.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.88-94
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• 2012

This study was carried out in order to investigate the effect of temperature of treatment and storage on the longevity of 'Unicorn' tomatoes of light red maturity stage during commercial handling conditions encountered while exporting over long distances. Tomato stored at $5^{\circ}C$ and $11^{\circ}C$ temperature with 85% relative humidity by pre-treating handling temperature that was using from field to before shipment as a winter temperature $5^{\circ}C$, spring temperature $11^{\circ}C$ and summer temperature $25^{\circ}C$ for 3 days. On the final storage day, $25^{\circ}C/11^{\circ}C$ (treated/stored) tomatoes showed the highest respiration and ethylene production rate; whereas the lowest respiration and ethylene production rate was found for $5^{\circ}C/5^{\circ}C$ treated and stored tomatoes. Tomatoes treated and stored at $5^{\circ}C/5^{\circ}C$ showed higher marketability, without evidence of fungal rot, decay or spots for 23 days. The fresh weight loss under all treatment conditions increased gradually during $5^{\circ}C$ and $11^{\circ}C$ storage temperatures. The higher firmness and soluble solids were determined from $5^{\circ}C/5^{\circ}C$ and $5^{\circ}C/11^{\circ}C$ treated and stored tomatoes repectively, than from others tomatoes on the final day of storage. In addition, $5^{\circ}C/5^{\circ}C$ tomatoes showed higher vitamin C contents than tomatoes stored at other temperatures, on the final day of storage. As the ripening and storage period progressed, the titratable acidity increased, but declined (P < 0.05) thereafter, due to over ripe tomatoes under all treatment conditions. These results show that $5^{\circ}C/5^{\circ}C$ treated and stored light red maturity stages of 'Unicorn' tomatoes are optimum to export because they show the highest storability and marketability. Moreover, the marketability of light red maturity stage of 'Unicorn' tomato maintained for 2 weeks in $25^{\circ}C/11^{\circ}C$ treated and stored temperature that might be the export temperature from Korea to Japan in summer season. This research result could be useful in helping tomato growers and exporters to get optimum market value by satisfying the buyer and consumer with a fresher product.