• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.5
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• pp.19-28
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• 2016

This study was to design the optimal locations of the water level monitoring to quantify the agricultural water use in irrigation area supplied from an agricultural reservoir. In most of agricultural areas without TM/TC (Tele-Monitoring and Tele-Control) or monitoring network, irrigation water have been supplied on conventional experience and agricultural reservoir have been operated based on the operating simulation results by HOMWRS (Hydrological Operation Model for Water Resources System). Therefore, this study quantified the amount of agricultural water use in an irrigation area (Musu Reservoir, Jincheon-gun) by establishing water level monitoring network and analyzed the agricultural water saving effect. According to the evaluation of the economic values for water saving effect, the saving agricultural water of 1.7 million ton was analyzed to have economic values of 0.85 million won as water for living, and 1.78 million won as water for industrial use. It is identified to secure economic feasibility of the new water monitoring network by establishing one monitoring point in the entrance, irrigation area and endpoint through the economic analysis.

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.223-226
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• 2001

The leaf water relations and photosynthetic rate during acute soil drying were compared in potgrown grapevine cultivars, Vitis vinifera cv. Chardonnay and V. vinifera cv. Riesling. Leaf water potential in Riesling decreased significantly from day 2 after water had been withheld, while in Chardonnay leaf water potential for the water-stressed plants was almost identical with that in well watered plants during the first 4 days. Higher stomatal conductance and photosynthetic rate in Chardonnay than Riesling were observed until day 3 after withholding water. Photosynthetic rate in water-stressed Chardonnay was not different from that in control plants until day 3 after withholding water, while that in water-stressed Riesling was reduced markedly from day 2. In Riesling, osmotic potential at turgor loss point was not changed irrespective of watering conditions. However, in Chardonnay osmotic potential at turgor loss point decreased more in the water stressed conditions than in well watered conditions. The osmotic adjustment in Chardonnay under water stress conditions must contribute to the maintenance of higher stomatal conductance and photosynthetic rate than those in Riesling for a significant period of the drying process. Though difference in stomatal conductance between the two cultivars was shown in the process of soil drying, stomatal conductance of both cultivars responded to vapor pressure difference between leaf and ambient air, rather than soil water status and leaf water potential.

• Corrosion Science and Technology
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• v.21 no.5
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• pp.327-339
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• 2022

The water-jet technique started by Bridgman can cut metal and alloys without harmful gas and fume. However, while this technique is convenient to cut metals and alloys, in the case of coated pipe, water jet induces the degradation of coatings on the pipes, and may facilitate structural failure, leakage, and loss of products. While there are many reports on the effect of water jet on cut metals and the damage of metallic materials, research on the effect of water impingement on the epoxy coatings has been little studied. In this work, we therefore control the velocity of water jet, distance between nozzle and specimen, and water temperature, and discuss the effect of water impingement on the epoxy coatings. Increasing water velocity and water temperature and reducing nozzle distance increased the degradation rates of three epoxy coatings were increased. Among three test parameters - water velocity, nozzle distance and water temperature, water temperature was relatively effective to increase the degradation rate of epoxy coatings.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.195-202
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• 2003

Chitosan is known to have antibacterial, antitumorogenic, hypolipidemic and immunopotentiating activities, hence finding diverse uses as a component in varying functional foodstuffs. However, some investigators reported it caused mineral absoiption inhibition and excess coagulation. From the chemical viewpoint, conventional chitosans are high-molecule polymers lacking water solubility, which could be related with their possible toxicity. A newly developed low- molecule water soluble chitosan is thought to have low toxicity compared to conventional chitosans. But no investigation was carried out to evaluate its toxicity. In this study, a 28-day subacute oral toxicity study of the water-soluble chitosan was performed in Sprague-Dawley rats of both sexes. Each 36 male and female rats were orally administered with 500, 1,000 and 2,000 mg/kg/day for 28 consecutive days, respectively. Clinical parameters (growth rate, feed and water consumption, daily inspection, urine analysis) during the 28 days indicated the water-soluble chitosan did not induce any abnonnal changes. There were no abnormal findings due to the administration of the test substance in gross and microscopic findings. We had not found alteration in absolute and relative organ weight between the control and treated groups, with only exception in the liver but lacking dose-dependency. The results of hematology and serum biochemistry examination revealed that no treatment related changes were between control and all dose groups. In conclusion, it was suggested that subacute toxicity of the water-soluble chitosan was low and the no-observed adverse effect level was considered to be over 2,000 mg/kg in rats.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.4
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• pp.331-336
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• 1990

In order to evaluate the adaptability of Aardi goats to arid environment, 5 Aardi bucks were deprived of water for four days during spring and summer seasons. The rise in average maximum ambient temperature from $24.8^{\circ}C$ in spring to $35.8^{\circ}C$ in summer caused a significant rise in rectal temperature ($0.3^{\circ}C$), respiratory rate (62%), serum osmolaity (8%) and serum sodium concentration (17%). While, it resulted in a significant decline in dry matter intake (50%), urine volume (74%) and fecal water excretion (60%) compared with their values in spring, but had no significant effect on the volume of drinking water. At the end of the 4-days deprivation period during spring, respiratory rate, dry matter intake and urine volume were reduced by 18, 77 and 91% relative to their average in control goats. The corresponding reduction in summer were 58, 100 and 100%. Serum osmolaity was risen by 15% in spring deprived goats and 29% in summer deprived goats. Rectal temperature rose by a mean value of $1.3^{\circ}C$ only in goats deprived of water in summer. Percent of moisture in the feces declined from 64 in control goats, to 24% in water deprived goats during spring season. The corresponding values in summer were 25 and 6%. These responses of Aardi goats deprived of water in summer indicate that they possess a water economy mechanism enable them to tolerate infrequent drinking in hot-arid environment.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.27-31
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• 2005

Objectives : The anticancer response of three different types of water extracts of Zingiberaceae Curcuma longa L. tested for sarcoma 180. Only few studies carried out to investigate the effects of other contents of Curcuma longa L. in anticancer activities, therefore, in this study we have investigated the effects of other component then curcumin in Curcuma longa L. for anticancer a activities. Methods : Three different types of water extracts of Curcuma longa L. were prepared as follows. The sarcoma cells (S180) were maintained in Dulbecco's modified Eagle's medium (DMEM) and were seeded on 24-well cell culture cluster flat bottom with lid tissue culture treated non-pyrogenic polystyrene. The growth of sarcoma 180 was monitored for 1, 2 and 5 days. The sarcoma cells were pictured using inverted microscope and cell density was counted using hemocytometry. Results : After 5 days in the culture medium the results showed high growth of sarcoma 180 for control condition and the surface of CCP plates were fully covered with the cells. In case of medium in which the 10% of filtered water extract of Curcuma longa L. was added a very limited growth of sarcoma 180 was observed. The results were showed only small difference in cell density for two different concentrations of unfiltered water extracts of Curcuma longa L. whereasin case of filtered water extracts the control of sarcoma growth shows better result. Conclusion : The filtered water extracts showed the best result relatively to the unfiltered water extracts for two different concentrations. This indicates that the water extracts of Curcuma longa L. can have anticancer activities possibly without curcumin.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.168-172
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• 1996

The soil moisture content and its relation to plants may be important in determining the crop growth and yield. The present study was undertaken to evaluate the leaf water potential and photosynthetic activity in soybean plants as affected by the timing of soil water stress. The soybean variety, 'Tachinagaha', was grown in a pot. The 15 day-old seedlings were subject to the three levels of soil moisture content(25, 40 and 55%) for 25 days. Then the treated soybean plants were placed again at the level of 25% soil moisture content for 25 days, and were compared with the control which was well-watered at 40% level for whole growth period. Soybean plants grown under continuous drought showed higher apparent photosynthetic rate(AP) than those under well-watering /drought in the first /second water treatment, suggesting that AP was adjusted after previous acclimation to drought. Over a wide range of photosynthetic photon flux densities(PPFD), drought or excessive water stress resulted in the decrease in AP when compared with the control. AP and stomatal conductance were decreased in soybean plants subject to water deficit stress, suggesting that AP and stomatal conductance were more sensitive to drought than excessive water stress.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.48-56
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• 2018

Objective: The purpose of this study was to determine the effects of carbonated water on etched or sealed enamel according to the carbonation level and the presence of calcium ions. Methods: Carbonated water with different carbonation levels was manufactured by a soda carbonator. Seventy-five premolar teeth were randomly divided into a control group and 4 experimental groups in accordance with the carbonation level and the presence of calcium ions in the test solutions. After specimen preparation of the Unexposed, Etched, and Sealed enamel subgroups, all the specimens were submerged in each test solution for 15 minutes three times a day during 7 days. Microhardness tests on the Unexposed and Etched enamel subgroups were performed with 10 specimens from each group. Scanning electron microscopy (SEM) tests on the Unexposed, Etched, and Sealed enamel subgroups were performed with 5 specimens from each group. Microhardness changes in different groups were statistically compared using paired t-tests, the Wilcoxon signed rank test, and the Kruskal-Wallis test. Results: The microhardness changes were significantly different between the groups (p = 0.000). The microhardness changes in all experimental groups except Group 3 (low-level carbonated water with calcium ions) were significantly greater than those in the Control group. SEM showed that etched areas of the specimen were affected by carbonated water and the magnitude of destruction varied between groups. Adhesive material was partially removed in groups exposed to carbonated water. Conclusions: Carbonated water has negative effects on etched or sealed enamel, resulting in decreased microhardness and removal of the adhesive material.

• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.581-589
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• 2013

Generally, Sewage Treatment Plants(STPs) are complexes systems in which a range of physical, chemical and biological processes occur. However, their performance strongly depends on the know-how acquired by the field-engineer. Recently, in order to solve this situations, various operation and management technologies based on the Instrumentation, Control and Automation(ICA) have been developed. As a economies-environmental affect point of view, this study was for the performance evaluation and assessment of results from the Smart Operation System(SOS) in full-scale STP. The SOS in STP consisted of the process monitoring module, including real-time influent prediction and effluent simulation, and the Smart Air Control(SAC) module. According to the results from field test for 2 years, the results of economical evaluation, amount of benefits and cost saving by the SOS have shown to be much higher than that of traditional operation. Nevertheless, the removal load(kg/yr) of BOD 13.3 %, COD 28.2 %, TN 44.4 % and TP 20.8 % were increased, respectively. Remarkable improvement of removal load could be achieved after the SOS was adapted. It was concerned that the SOS offer a user friendly functionalities and cost saving needed by the field-engineers. In addition, it was expected that the results of this study would supply helpful information for design and cost saving for the SOS in full-scale STP.

• The Korean Journal of Community Living Science
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• v.14 no.2
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• pp.41-47
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• 2003

To investigate the effects of hot water soluble extract from Angelicae Gigantis Radix on lipid metabolism and antioxidant defense system in rats fed hypercholesterol diet, Sprague-Dawley male rats were fed either hypercholesterol diet with water or hot water soluble extract from Angelicae Gigantis Radix. Hypercholesterol diet contained 18 % beeftallow and 5 % cholesterol. After 4 weeks of experimental periods serum and liver obtained. The level of serum lipid and the activities of GOT and GPT was measured. The level of lipid and TBARS and the activity of GSH-Px was measured also. The results obtained were: 1) Food intake in the experimental group supplied hot water soluble extract from Angelicae Gigantis Radix was low significantly. 2) In the experimental group supplied hot water soluble extract from Angelicae Gigantis Radix of serum total lipid and total cholesterol was significantly low. 3) Serum GOT activity was significantly low in the experimental group supplied hotwater soluble extract from Angelicae Gigantis Radix. There was no difference of serum GPT activity between control and experimental group supplied hot water soluble extract from angelical Gigantis Radix. 4) There was no difference of lipid composition, TBARS level and GSH-px activity in liver between control and experimental group. The result of this study indicates that the hot water soluble extract from Angelicae Gigantis Radix was effective in decreasing the food intake of the experimental animals in the hypercholesterol diet and also effective in decreasing the levels of serum total lipid, total cholesterol and GOT activity. However it was not effective to change the level of lipid, TBARS and GSH-Px activity of liver.