• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.271-282
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• 1982

The browning development, mainly through the Maillard reaction, occurring in the dried fish meat products during storage causes reduction of the nutritional value due to the loss of the essential amino acid such as available lysine as well as off -flavor resulting in the deterioration of the food quality thus shortening the shelflife. In the work, the changes in the amount of available lysine, extractable nitrogenous compounds (nonprotein-N, amino-N, trimethylamine oxide, trimethylamine, and free lysine) and development of browning were measured to assess the relationship between the shelflife and the quality loss in dried filefish under the steady state conditions (35,45, and $55^{\circ}C;a_{w}'s$ of 0.44 0.52, 0.65 and 0.75 at each temperature) and fluctuating temperature condition of $35/55^{\circ}C$ will. alternating 7 day periods at each water activity. The results indicated that the amount of available lysine and extractable nitrogenous compounds except TMA decreased rapidly with increasing temperatures and water activities while the rate of available lysine and extractable nitrogenous compounds must be involved in the initial stage of brown pigment formation. The available lysine loss of the dried filefish products stored under the fluctuating temperature conditions was greater than that stored under its fixed mean temperature, $45^{\circ}C$. The activation energies for lysine loss obtained from the Arrhenius plot ranged 6.9 to 4.4 Kcal/mol and $Q_{10}$ values at $40^{\circ}C$ were 1.4 to 1.2. The values for browning were 15.7 to 14.4 Kcal/mol and 2.2 to 2.0 respectively. Shelf-life, defined as the time to reach 0.15 O. D./g solid or the limit of off-color deterioration by browning reaction, was extented longer than the halflife of Iysine loss, actually corresponding $75\%$ loss of available lysine. This suggested that the halflife of lysine loss might not be adequate to assess the shelf-life of the food system with high potential of protein, nonproteinous nitrogen compounds, and lipids.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.130-138
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• 1987

The effects of light and storage conditions on the germination of Oenothera lamarckiana were investigated. Germination was induced by red light, but inhibited by green, blue or infrared. No germination occurred in the dark. Radicle was more photosensitive than other parts of the seed. The rate of germination was proportional to increase in Light intensity ranging from 10 to 3000 Lux. Photosensitivity occurred 6 hrs after water imbibition of air-dried seeds. Maximum photosensitivity was detected 1-2 days after seeding under the light condition at 300 Lux. Germination was almost completed 3 days after seeding. When seeds stored in the chilling and wetting condition were kept at constant temperature in the dark, they germinated well. Air-dried seeds, however, didn't germinate. Whereas, the seeds which kept at alternating temperature had the tendency that seeds stored at room temperature (25$^{\circ}C$) germinated better than those stored at low temperature (4$^{\circ}C$).

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.791-798
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• 1994

Ohmic heating is a food processing operation in which heat is internally generated within foods by the passage of alternating electric current. The process enables highly viscous paste foods such as Kochujang, and fermented soybean paste to be heated very fast. In order to develope the novel pasteurization process of paste foods, static Ohmic heating system was built, and heating characteristic during Ohmic heating under various conditions were studied. Electric conductivities of Kochujang and fermented soybean paste at room temperature were 1.865 S/m and 2.510 S/m, respectively and increased linearly with increasing temperature. Specific heating rate was highly dependent on the frequency. The highest heating rate was achieved at 5 KHz for Kochujang and 20 KHz for fermented soybean paste. Uniform heating throughout the sample was achieved during Ohmic heating with low frequency electrical currents, however above 5 KHz frequency, surface temperature was several degrees higher than the bulk.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.160-166
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• 2011

The purposes of this study were to analyze the weediness potential associated with 'Vitamin A enforced rice' and to evaluate the relationships between growth characteristics and environmental adaption related to survival ability in the natural environment. 'Vitamin A enforced rice', 'Nagdong', donor variety of 'Vitamin A enforced rice' and three other varieties were used for this study. The 'Vitamin A enforced rice' was experimented according to ratio of ripened grain, shattering of grain, germination traits, germination ratio of low temperature, emergence ratio after wintering, ratio of viviparity, and growth ratio after ratooning ability. 'Vitamin A enforced rice' was not significant between 'Nagdong' and other varieties in seven characters. Germination ratio was similar of Vitamin A enforced rice' and 'Nagdong', but average germination ability of was different at low temperature. Also, shattering of grain and germination ratio of alternating temperature were significant between 'Nagdong' and other varieties. These results suggested that the relationships between growth characteristics and environmental adaption in 'Vitamin A enforced rice' could be applied to the stability of weediness potential and biosafety guide in GM rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1515-1521
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• 2004

As one of the research series for the industrialization of sikhae, this study was evaluated the taste compounds present in different temperature conditions, $5^{\circ}C$, $20^{\circ}C$ and alternating temperature (stored at $5^{\circ}C$ after 10 days fermentation at $20^{\circ}C$), respectively. The changes in proximate compositions were negligible but the amounts of total sugar decreased during fermentation. The pH of sikhae products except the product fermented at $5^{\circ}C$, decreased during fermentation and was maintained at the rage of 3.8~4.4 after 10 days. The values of acidity, VBN and amino-N gradually increased with fermentation times and with increasing temperature condition in all products. Three organic acids (lactic, citric and malic acid) were disclosed as key compounds affecting the sourness in Alaska pollack sikhae. The result of taste value revealed that 6 amino acids having sweet and umami taste (aspartic acid, glutamic acid, alanine and lysine) and bitter taste (valine and methionine) as major amino acids affecting the taste of sikhae products, and increased with fermentation times. Hypoxanthine was the main component in ATP related compounds. Amino-N was comprised more over 50% of the Ex-N in sikhae products, and followed by total creatinine-N, TMAO-N and TMA-N in that order.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.79-86
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• 2024

This study was conducted to determine the conditions for breaking dormancy in the seeds of the North Korean plant resource, Trollius macropetalus, and to investigate its germination characteristics. The morphological characteristics and viability of T. macropetalus seeds were examined. Germination characteristics were investigated based on temperature conditions (15/6℃ & 25/15℃), cold stratification treatment, and GA₃ treatment. The results showed that cold stratification treatment had no effect on breaking the dormancy of T. macropetalus. GA₃ treatment significantly increased the germination rate of T. macropetalus and also improved the mean germination days and germination speed. However, compared to the 15/6℃ condition, the effectiveness of GA₃ treatment for T. macropetalus decreased under the 25/15℃ condition. It was determined that T. macropetalus have a nondeep-type morpho-physiological dormancy. The most effective conditions for breaking dormancy were found to be the 15/6℃ temperature condition and GA₃ treatment at 500 mg·L^-1. The findings of this study are expected to provide valuable information for the mass propagation of T. macropetalus, which has potential applications in landscaping and pharmaceutical materials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.662-669
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• 1995

To clarify the effect of temperature during ripening on grain quality, rice plant which was grown under normal natural conditions untill heading stage was subjected various temperature regimes during grain filling stage. Three varieties, Odaebyeo, Hwaseongbyeo and Dongjinbyeo were used. Grains on primary and secondary-rachis branches were harvested seperately and measured specific gravity, grain size and weight. The optimum daily temperature for grain filling of rice during ripening period was about 22$^{\circ}C$ and grain filling under alternating temperature(26/18$^{\circ}C$, day /night) was better than constant temperature (22 /22$^{\circ}C$) based on 1, 000-grain weight and yield. Grain size based on volume per grain was smallest under the constant temperature of 22 /22$^{\circ}C$. The size of secondary-rachis branches was smaller than primary-rachis branch. The difference in size between primary and secondary-rachis branches was biggest in Hwaseongbyeo, followed by Odaebyeo and Dongjinbyeo. The temperature regimes treated did not influence the grain size difference between branches so much. The 1000-grain weight was lighter under high temperature than low temperature in Odaebyeo, but reversed tendency was observed in Dongjinbyeo of secondary rachis-branches.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.493-500
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• 2014

Nonlinear characteristics of cellular counterflow diffusion flame near the radiative extinction limit at large Damk$\ddot{o}$hler number are numerically investigated. Lewis number is assumed to be 0.5 and flame evolution is calculated by imposing an infinitesimal disturbance to a one-dimensional(1-D) steady state flame. The early stage of nonlinear development is very similar to that predicted in a linear stability analysis. The disturbance with the wavenumber of the fastest growing mode emerges and grows gradually. Eventual, an alternating pattern of reacting and quenching stripes is developed. The cellular flame temperature is higher than that of 1-D flame because of the gain of the total enthalpy. As the Damk$\ddot{o}$hler number is further increased, the shape of the cell becomes circular to increase the surface area per unit reacting volume. The cellular flames do not extinguish but survive even above the 1-D steady state extinction condition.

• Journal of the Korean Electrochemical Society
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• v.14 no.4
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• pp.225-230
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• 2011

CIGS solar cells are kind of thin film solar cells, which are studied several years. CdS buffer layer that makes heterojunction between window layer and absorbing layer was one of issue in the CIGS solar cell study. New types of buffer layer consisted of indium sulfide are being studied these days owing to high price and environmental harmful of CdS. In this study, we demonstrated electrochemical synthesis of indium sulfide film as a buffer layer, which is cheaper and faster than other methods. A uniform indium sulfide film was obtained by applying two different alternating potentials. The band gap of the film was optimized by controlling temperature during the electrochemical synthesis. Using x-ray photoelectron spectroscopy and diffraction method we confirmed that ${\beta}$-indium sulfide was formed on ITO electrode surface.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.813-822
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• 1996

In order to reduce carbon dioxide, one of the major greenhouse gases, a new type of copolymer, poly(alkylene carbonate) has been synthesized. The alternating copolymers have been obtained from carbon dioxide and various epoxides with zinc carboxylate as a catalyst. The number-average molecular weight of the polymer is about 50,000 and polydispersity is rather broad(5~10). The polymers are amorphous, and glass-clear materials that exhibit unusually facile and clean thermal decomposition behavior. Complete decomposition with no carbon residue is observed at elevated temperature even in an inert atmosphere. Terpolymers with bulkier epoxides improve the physical properties of the copolymer with simple epoxides. The decomposition properties of the polymer provide versatile applications such as ceramic, metal, and electronic binders and lost-foam casting. Further application of the polymer for the barrier film or the plasticizer will be investigated.