• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.92-100
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• 2017

The Helicopter MRA Control Rod System has the important function of controlling the speed, height, and direction of helicoptersby adjusting the main rotor disc. However, the ingress of water into the inner control rod can cause ice damage in the rod during winter operation and also corrosion;these defects need to be rectified. The water flowed into the control rod through the upper side space, and the rod was cracked during icing expansion occurring at low temperature. The corrosion occurred due to the lack of coating process during the manufacturing process. To resolve these problems, the upper rod was sealed to prevent water inflow and a coating process was added to prevent corrosion. These solutions were verified by awaterproof test and a salt fog test. The phenomena, causes and measures were reviewed and the methods of improvement were established and proven. This proposed technology to prevent water infiltration and corrosion will contribute to the safety of rotary wing aircraft.

• Food Science and Preservation
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• v.17 no.1
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• pp.123-130
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• 2010

We compared physiological activities in reflux extracts from Liriope platyphylla leaves and roots. The water extract of roots had the highest solid extraction yield of 53.96%. The greatest level of total polyphenols was 186.88 mg/g in methanol extracts from leaves, whereas water extract from leaves showed the highest concentration of flavonoid compounds, at 159.29 mg/g. The leaf extract had 97.42% of the electron-donating ability (EDA) of the positive control, at 0.5 mg/mL. The superoxide dismutase (SOD)-like activity of water extract of leaves was 9.75% of the positive control value, at 1.0 mg/mL. The nitrite scavenging ability of methanolic extract from leaves was highest, at 40.56% of the positive control level at pH 1.2 and a concentration of 1.0 mg/mL, whereas root extracts were ineffective in this regard. Inhibition of xanthine oxidase by leaf extracts was more than 99% of the positive control value at 1.0 mg/mL, whereas water and methanolic root extracts had activities of 93.75% and 68.47%, respectively. When tyrosinase inhibition was examined, the water extract of leaves had 22.80% of positive control activity but methanolic extracts were inactive. These results indicate that leaves of L. platyphylla will be more useful for development of functional products than the roots, which are used to make medicinal preparations.

• Journal of Animal Science and Technology
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• v.56 no.5
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• pp.18.1-18.5
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• 2014

Background: A six-week study involving two hundred and fifty (250) Harco Black layer birds at point of lay was conducted to investigate the effects of potential natural colorant on performance and Egg quality traits. The birds were assigned to five (5) dietary treatments, each containing supplements either of control, Baobab Leaf (BL), Waterleaf (WL), Red Pepper (RP), Canthaxanthin (CTX) at 40 g/kg feed and 50 mg/kg feed of natural and commercial colorants, respectively. Results: Performance records shows that there was no significant (p > 0.05) difference in feed intake across the supplements of Red pepper, Water leaf, Canthaxanthin and control diet, however, birds fed Baobab leaf treatment had a significantly lower (p < 0.05) feed intake value (94.07 g) when compared with other treatments. Body weight gain and Hen Day Production were not significant influenced (p > 0.05) by the dietary treatments, although laying hens fed Baobab leaf supplement had lowest mean HDP of 48.80%, while birds fed Red pepper and Water leaf supplement had an average value of 52.79%. There was no significant effect (p > 0.05) of colorants on egg external traits, compared with the control; birds fed Canthaxanthin treatment had higher mean egg weight (51.79 g), egg length (4.55 g), egg breadth (3.29 g); Red pepper treatment had highest mean shell thickness (0.29 g), however these differences were not significant (p > 0.05). Yolk height, Albumen height, Yolk index, and Haugh unit were not significantly affected (p > 0.05) across treatments. Yolk width was lowest (p < 0.05) in Baobab leaf treatment (2.54 cm); Red pepper, Water leaf and Canthaxanthin (2.89 cm, 2.62 cm and 2.89 cm respectively) were not significantly (p > 0.05) different from the control (2.73 cm). Yolk colour score was significantly highest (p < 0.05) in Red pepper treatment (7.50); Water leaf, Baobab leaf and Canthaxanthin ranged between 2.25-3.31 on the DSM yolk colour fan, Control treatment had the lowest yolk colour score (p < 0.05) of 1.31. Conclusion: The study showed Red pepper as a worthy alternative to commercial yolk colorant. Water leaf and baobab are not good substitutes for canthaxanthin as a yolk colourant.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.200-208
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• 2003

This study was carried out to investigate the influence of dietary germanium supplementation on the meat quality of duck. Ducks raised for 42 days were slaughtered and the ground meats were stored at 3$^{\circ}C$ for 12 days under 1200 lux. Experimental treatments were divided into 3 kinds of meat from ducks fed germanium as follows; 1) Control(natural water + commercial feed), 2) T1(1～10 days: natural water + commercial feed, 11-42 days: natural water + commercial feed supplemented with 1 % germanium), 3) T2(1～10 days: germanium submersion water + commercial feed, 11～42 days: natural water + commercial feed supplemented with 1 % germanium). The pH of duck meat was not different among the treatments(p>0.05). The germanium treatments exhibited significantly higher crude fat content in both breast and thigh meat(p<0.05). In the fatty acid composition, T2 contained more unsaturated fatty acid than control or Tl. TPA(textural profile analysis) value such as hardness, gumminess, chewiness and adhesiveness decreased in meat from duck fed supplemental germanium. Cholesterol contents of duck meat decreased in dietary supplemental germanium treatment compared to control, but were not significantly different among them(p>0.05). Dietary germanium supplementation affected on lipid oxidation of meat during storage. TBARS of meat from duck fed germanium was lower than that of control(po.05). The CIE L*, b* and h$\^$0/ values of germanium treatments were significantly(p.o5) higher than those of control. Also a* value showed more stable in germanium diet treatment during storage. Therefore, dietary supplemental germanium to duck resulted in light brownish color formation, improvement tenderness and retardation of lipid oxidation of meat during refrigerated storage.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.222-227
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• 2002

Efficacy of submersion aging in chilled water of vacuum-packed Hanwoo beef was investigated. At 24 hours post-mortem, the somimemebranosus portion of Hanwoo carcass was excised and sliced (2.5cm, thickness). After beef core samples(6$\textrm{cm}^2$${\times}$2cm) were prepared and vacuum packed, the samples were randomly assigned to the four treatments which were conventional refrigerator at 4$^{\circ}C$(control), conventional refrigerator at 1$^{\circ}C$(T1), submersion in chilled water at 4$^{\circ}C$(T2) and submersion in chilled water at 1$^{\circ}C$(T3). Samples were stored for 3, 7, 10 and 14 days to measure meat color(CIE L*, a*, b*), deoxymyoglobin, oxymyoglobin and metmyoglobin percentage, thiobarbituric acid reactive substance (TBARS) value, purge loss(%) and total heam pigment content. CIE a* value of samples was not significantly changed by treatment during the storage. However, metmyoglobin content of T2 samples was significantly (p<0.05) lower than those of control and T1,T3 during storage. Also, TBARS value of T3 samples was significantly (p<0.05) lower than those of control and T2 samples. T3 showed the lowest purge loss%, whereas control remarked the highest purge loss(%). Total heam pigment of all samples were not significantly changed during the storage. These results suggested that submersion aging in chilled water could keep the myoglobin stability and reduce lipid oxidation and purge loss of vacuum packed beef during storage.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.228-233
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• 2002

To investigate the effects of submersion aging in chilled water on tenderness and microbial growth of vacuum-packed beef, the semimembranosus muscles of Hanwoo (Korean cattle) was sampled at a commercial meat plant at 24 hrs postmortem. The samples were cut to 2.5 cm thick steaks and randomly assigned to following two treatments. The samples were stored in conventional refrigerator at 4$^{\circ}C$ after vacuum packaging for control whereas the other vacuum-packed samples were submersed in chilled water at 1$^{\circ}C$ for treatment, and both samples were stored for 14 days to measure total plate counts (TPC), sarcomere length, free calcium concentration, shear farce value and myofibrillar fragmentation index (MFI). The sarcomere length of treatment was significantly (p<0.05) longer than that of control at 3 days aging. Result suggested that submersion in chilled water of vacuum-packed beef might be effective to improve tenderness of meat compared to storage in conventional refrigerator. There were no significant differences in the shear force and MFI between control and treatment during storage. However, the free calcium concentration of samples from treatment was significantly (p<0.05) higher than that of control at 7 days of ageing. This result indicated that the lower shear force value and the longer sarcomere length of samples from treatment might be due to increasing the free calcium ion concentration in sarcoplasm during storage. On the other hands, samples from control showed significantly (p<0.05) higher number of microbial (TPC) compared to treatment during storage. from results obtained, submersion in chilled water of vacuum-packed beef could be recommended as a desirable aging method to improve tenderness of Hanwoo compared to aging in conventional refrigerator.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.57-57
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• 2022

In many areas of the world, salt damage and drought have had a negative impact on human survival due to a decrease in agricultural productivity. For instance, about 50% of agricultural land will be affected by salt damage by 2050. Biostimulants such as plant extracts can not only increase the nutrient utilization efficiency of plants, but also promote plant growth and increase resistance to abiotic or biotic stress. Therefore, the objective of this study was to determine how selected plant extracts might reduce levels of stress caused by drought and salt and to better understand the physiological response mechanisms of rice plants. In this study, we used Soybean leaves, Soybean stems and Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts were used. These extracts had been used in previous studies and were found to be effective. The materials were dried in a dry oven at 50℃ for 5 days and ground using a blender. Each 50 g of materials was put in 1 L of distilled water, stirred for 24 hours, filtered using 4 layers of mirocloth, and then concentrated using a concentrator. Rice (cv. Hopumbyeo) seeds were immersed and germinated, and then sown in seedbeds filled with commercial soil. In drought experiments, three rice seedlings at 1 week after seeding was transplanted into 100 ml cups filled with commercial soils and grown until the 4-leaf stage. For this experiment, the soil weight in a cup was equalized, and water was allowed to become 100% saturated and then drained for 24 hours. Thereafter, plant extracts at 3% concentrations were applied to the soils. For NaCl treatments, rice plants at 17 days after seeding were treated with either 100 mM NaCl or plant extracts at 1%+ 100 mM NaCl combinations in the growth chamber. Leaf injury, relative water content, photosynthetic efficiency, and chlorophyll contents were measured at 3, 5, and 6 days after treatments. Shoot fresh weight of rice under drought conditions increased 28-37% in response to treatments of Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Shoot fresh weight of rice subjected to 100 mM NaCl treatments also increased by 6-24% in response to Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Compared to the control, rice plants treated with these six extracts and subjected to drought conditions had significantly higher relative water content, Fv/Fm, total chlorophyll and total carotenoids than control plants. With the exception of relative water contents, rice plants treated with the six extracts and subjected to salt stress (100 mM NaCl treatments) had significantly higher Fv/Fm, total chlorophyll and total carotenoids than control plants. However, the type of extract used did not produce significant difference in these parameters. Thus, all the plant extracts used in this study could mitigate drought and NaCl stresses and could also contribute substantially to sustainable crop production.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.732-734
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• 1997

This paper describes the design and implementation of a fuzzy temperature control system to control the water temperature in plant. For evaluating the performance of a fuzzy controller, the experiment results of a fuzzy controller are compared with these of a conventional PID controller which provides an auto-tuning function. The experiment results show that the proposed controller has a good control performance and is robust to external disturbance.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.196-204
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• 2022

This study observed changes in survival, growth performance and water quality for 90 days to confirm the possibility of Leiocassis ussuriensis farming using Biofloc technology (BFT) using Bacillus subtilis. Feed and molasses were added to the experimental tank to produce BFT water before planting the experiment, and B. subtilis was inoculated to stabilize the water quality for 40 days. The survival rate of the experimental fish was 92.7±3.2% in the control group and 95.8±3.3% in the BFT group. The Weight gain (WG) was 118.1±9.0% of the control and 197.7±15.6% of the BFT, and the Specific growth rate (SGR) was 0.87±0.5% of the control and 1.21±0.06% of the BFT. As for the feed efficiency, the control was 43.7±2.6% and the BFT was measured at 70.1±4.1%, indicating that the feed efficiency of the BFT was higher. As a result of measuring the water quality change during the experimental period, pH was reduced in both the control and the BFT, and Mixed Liquor Suspended Solids (MLSS) did not show any change in the control, but the BFT showed a significant increase at 90 days. NH₄⁺-N and NO₂^--N showed a significant increase from the 30 days of the experiment in the control, but showed no change in the BFT. In conclusion, as a result of applying the BFT system using B. subtilis to the process of cultivating Leiocassis ussuriensis, the water quality tended to stabilize, and the growth rate and feed efficiency were found to be higher than those of the control, confirmiWng that it had a positive effect.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.207-211
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• 1996

This study was conducted in the sandy loam soil to find out the effects of fly ash and zeolite applications on saving of irrigation water which was required great quantities during the cultivation days of dry seeded rice. Total water loss was reduced so rapidly in the early growth stage that n was the least in the 18th day after irrigation. After that day it was increasd due to the growth development and the rising temperature. In the daily mean of decreasing water level during the whole irrigation days, control was 47.7mm but the treatments of fly ash and zeolite were 31.8mm and 35.8mm respectively Amounts of the presumed irrigation water of fly ash and zeolite treatments were lower about 29.1% and 20.9%. respectively than that of control during the whole irrigation days These gaps between control and amendment treatments were greater in the early growth stage than in the late stage Hardness, bulk density and the ratio of solid phase in the soil after experiment were the highest in the fly ash treatment and those of control and zeolite treatments were showed the same trends each other. Amounts of water percoration of control and zeolite treatments in the soil were increased 8.2% and 2.6% respectively in comparision with those in the soil after amendment application, but that of fly ash treatment was decreased 42.5%, In contrast to the water percoration of control in the soil after experiment, those of fly ash and zeolite treatments were decreased 76% and 32%.