• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.821-829
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• 2019

This study was conducted to evaluate the applicability of the extracts from nipa palm, molokhia, and finger root in functional cosmetics as a natural active ingredient. The extracts were obtained through the processes of heating under reflux with ethanol, filtration, concentration, and freeze-drying. UV absorption and blocking effects of the extracts were examined by using the UV-vis spectrophotometer equipped with an integrating sphere. Antioxidant activity and its stability between the extracts were compared using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Also, total polyphenol content in the extracts was determined quantitatively using the Folin-Ciocalteu reagent, with gallic acid as the standard. Antibacterial activity of the extracts was investigated by the disc diffusion test against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). Finally, collagenase inhibitor assay was performed to examine the anti-wrinkle effect of the extracts. From the results of this study, the extract of nipa palm showed the potential for use in cosmetics as an antioxidant and anti-wrinkle agent, and the extract of finger root as a sunscreen and antibacterial agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.143-148
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• 1984

Frozen sardine meat paste for fish sausage was prepared to obtain the basic data on improving the quality of sardine sausage, and its gel formation ability was compared with meat paste from raw sardine. In addition, its quality stability was studied during frozen storage. For the preparation of frozen sardine meat paste, the addition of 4% of sorbitol and 0.3f of polyphosphate to the fish meat appeared effective to keep the processing suitability and storage stability. Also, the gel formation ability of the frozen sardine meat paste was not inferior to that of raw sardine paste.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.542-549
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• 1999

The hydrothermal extracts were produced from fish head and their functional properties were investigated. The extracts exhibited an antioxidative effect and synergistic effect with $\alpha$-tocopherol by measuring peroxide values. The $5\%$ solution showed more antioxidative effect than $1\%$ solution. The extracts showed cryopropective effect, but the effect was less than sucrose. The solubility of the extracts was over $70\%$ in the all range of pH, and its lowest solubility was shown in pH 3.0. The extracts exhibited an emulsifying activity less than sugar ester (EAI=34.72) and little higher than or similiar to egg white (EAI= 14.69). The extracts showed a relatively high foam activity. The osmolality of the hydrothermal extracts at $1.0\%$ concentration were 23$\~$31 mOsmole which were much lower than 317 mOsmole at $1\%$ NaCl.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.128-135
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• 2021

The possibility and effectiveness of cryopreservation was determined to assess survival rates and improve stock management of thawed embryos of Manila clam, Ruditapes philippinarum. The ideal freezing rates were designed and tested to allow cryoprotectants to equilibrate across the membrane during freezing. Survival rates ranging from 0 to 64.3% were obtained using a stepwise freezing protocol compared with 82.3% control rates. Embryos of Ruditapes philippinarum were equilibrated in 2 CPAs plus sea water for 10 min at 25℃ and then cooled at -1℃/min from 20℃ to -12℃. Straws containing more than 100 embryos were held at 12℃ for 5 min allowing equilibration after seeding and slowly cooled at 2℃/min. to -35℃ for 30 min for equilibration before quenching in liquid nitrogen. Dimethyl sulfoxide (DMSO) is the best cryoprotectant indicated for embryos of R. philippinarum with a survival rate of 64.3±3.28% in the presence of 2.0 M DMSO.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.27-36
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• 2014

Due to the latitudinal location of Korea, the seasonally frozen ground has been focused on as research topics such as the frost heaving under the asphalt road rather than the permafrost ground. However, the recent construction of the second Korean Antarctic research station, the Jangbogo station and the participation on the development of the natural gas pipeline in Russia arouse the research interests on the behavior of the permafrost ground. At the design process of the geotechnical structures on the permafrost ground, the evaluation of the creep characteristics of the frozen soil is very crucial. Since the domestic specification on the frozen soil testing does not exist currently, it is necessary to evaluate the creep characteristics of frozen soils systematically with regard to the affecting factors. Therefore, the creep characteristics of the frozen specimens of dense Jumoonjin sand were evaluated under various loads at -5 and $-10^{\circ}C$. Based on the test results, as the load became close to the strength and the temperature became lower, the duration of the secondary creep became shorter and more distinct tertiary creep responses were observed.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.82-89
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• 1986

This experiment was carried out to determine the optimum freezing and thawing rates of the hamster embryos. The female hamsters were induced to superovulate by intraperitoneal injections of 30 i.u. PMSG and mated with males of the same strain of 4 days the PMSG injection. They were killed and embryos were flushed from the oviduct and uterine horn on 3 days after mating. Embryos were flushed with a modified Dulbecco's phosphate-buffered saline and equilibrated with 1.5 M-dimethylsulphoxide by a 3-step procedure. The freezing rates of the samples were $1^{\circ}C/min$ from room temperature to $-6^{\circ}C$ and the samples were seeded at $-6^{\circ}C$. After being held for 3 min at the seeding temperature, the rates were $0.3^{\circ}C/min$ from $-6^{\circ}C$ to $-35^{\circ}C$. From $-35^{\circ}C$ to $-70^{\circ}C$, the rates were divided into $0.1^{\circ}C/min$, $1^{\circ}C/min$ and $10^{\circ}C/min$, respectively. At $-70^{\circ}C$ the samples were plunged directly into liquid nitrogen. The samples were thawed at $4^{\circ}C/min$ and $12^{\circ}C/min$ from $-196^{\circ}C$ to $37^{\circ}C$, and for 2 min in $37^{\circ}C$ water bath, respectively. The average numbers of ovulation points and embryos recovered were 35.1 and 27.0 appearing 77.0% recovery rates. Eight cell embryos in the embryos recovered were 24.8. The survival rates of embryos according to the freezing rates were 55.5~67.7% at $0.1^{\circ}C/min$, 58.8~64.9% at $1^{\circ}C/min$ and 40.5~44.7% at $10^{\circ}C/min$, respectively. The survival rates at $10^{\circ}C/min$ were significantly low. The survival rates of embryos according to the thawing rates were 53.5% at $4^{\circ}C/min$, 53.7% at $12^{\circ}C/min$ and 59.1% in $37^{\circ}C$ water bath. The survival rates, in $37^{\circ}C$ water bath were slightly higher, but we did not find any differences among them. In conclusion, the best freezing rates of hamster embryos were $1^{\circ}C/min$ from the room temperature to $-6^{\circ}C/min$, $0.3^{\circ}C/min$ from $-6^{\circ}C/min$ to $-35^{\circ}C$ and $-0.1^{\circ}C/min$ or $1^{\circ}C/min$ from $-35^{\circ}C$ to $-70^{\circ}C$. The hamster embryos thawed for 2 min in $37^{\circ}C$ water bath showed the best survival rates.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.789-792
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• 2008

Recently, the deteriorations of RC bridge decks on express-way are frequently observed. The major cause of deterioration for the RC concrete bridge decks exposed to de-icing chemiclas would be chloride-induced reinforcement corrosion. Therefore, Waterproofing is necessary for improvement of bridge deck durability and comfortable utility. In this study is to investigate the appearance of deterioration and properties of concrete core from the collect in a bridge deck. The results of this study shows that penetration waterproofing agents shows low infiltration depth and low water-repellent. It appears that the damaging of concrete deck is primarily waterproofing system rather than physical property.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.265-270
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• 1993

In order to retain the freshness of fruits and vegetables and to reduce the rate of disease damage, grafruit seed extract (GPSE), natural microorganism control agent, was applied during the preservation process of fresh fruits and vegetables. GFSE showed an effective inhibitory action against plant putrefactive bacteria and fungi which were involved in the decay of fruits and vegetables. Minimal inhibitory concentrations for GFSE against the microbes were in the range of 50 to 2,000 ppm. Direct observation of microbial cells and spores using electron microscopy showed their function was destroyed by the treatment of the dilute solutions of GFSE. Fresh Welsh onions, onions and red peppers treated with GFSE and stored in polyethylene film (0.1 mm) retained better quality in color and texture than the non-treated control. GFSE was efficient in controlling the germination of potatoes. It was observed that GFSE would reduce disease damages and have bactericidal and fungicidal properties during the storage of such fruits and vegetables as zucchinis, cucumbers, tomatoes and mandarin oranges.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.198-203
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• 2006

This study was conducted to select the temperature for hot air drying method, cutting method, and solution that inhibits enzymatic browning in making high quality powder from sweetpotato roots. It was observed that $70^{\circ}C$ was the best temperature for air drying method wherein the dry matter rating, dry matter time, flour yield and chemical component were considered. The proper cutting thickness should be 2.0 mm considering the vitamin C content and sensory evaluation of sweetpotato flour. Also, 1% vitamin C solution inhibited enzymatic browning of sweetpotato.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.4
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• pp.2419-2425
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• 1971

In many cold weather concrete constructison jobs calcium chloride $CaCl_2$ can be used safely as an accelerating admixture. For producing satisfactory concrete during cold weather calcium chloride is used to develop the level of strength required in a shorter period by obtaining higher early strength, the resulting in crease in heat of hydration. In this paper, to get adequated data and information of the effect on strength of concrete in using calcium chloride as an accelerating admixture, Portland cement (Type I), High-early-strength cement(Type II) and Pozzolans cement with certain 1.5 percentage of calcium chloride by weight of the cement were tested. As the result of this experiment, followings were founded: 1. At the 1.5 percent of calcium chloride cement ratio, the early strength was accelerated to the highest level, and some 1.5 percent of calcium chloride cement ratio was suitable for the stabilization of the concrete structures. 2. For Some 50 percent of Water Cement ratio was suitable, making good Concrete in the Cold weather by admixture of Calicum Chloide. 3. The concrete of Pozzorans cement in early strength was weak but that in later rised by degree. 4. As abtaining higher early strength the curing period can be reduced, but the finishing work should be done as early as possible.