• Composite Materials and Engineering
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• v.3 no.3
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• pp.167-178
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• 2021

In the present paper, the destructive behavior of distilled water, salty water, sulfuric acid, and heat on glass/vinyl ester composites was investigated by experimental methods. Hetron 922 vinyl ester resin and two types of mat and woven glass fibers as the reinforcements were used to fabricate composite test samples. All samples were immersed in distilled water, salty water, and sulfuric acid with three different concentrations. The tests were performed at 20℃ and 70℃ for the exposure duration of 1, 2, 4, and 8 weeks. Bending tests were performed after aging for all composite samples to check the degradation of the bending modulus and strength. The results show that the effect of distilled water, in comparison with salty water, on the degradation of composite samples was significant. On the other hand, almost non-sensitivity of concentrations of salty water on the weight gain of specimens has been observed. In addition, it was also observed that the degradation of samples at 70℃ temperature is much more than that of at 20℃. Also, it was observed that the flexural modulus of virgin specimens exposed to salty water (2% concentration) has been recovered just after two weeks of immersion. Furthermore, in some cases, composite samples under the sulfuric acid solution have lost almost 80% of their mechanical properties.

• Journal of the Korean Geographical Society
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• v.49 no.1
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• pp.18-31
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• 2014

In this study, the spatio-temporal patterns of salty wind by typhoon in Jeju Island and their damages to windbreak forests are examined. To investigate these patterns, field trips as well as analyses of meteorological data were conducted after the attack of typhoon BOLAVEN in late August, 2012. Collected data show that salty wind damage in windbreak trees by the typhoon was distinct in the southern and eastern coastal areas due to the southeasterly gusts with less precipitation. Most of trees including Japanese cedar (Cryptomeria japonica) within 8km from the coast as well as pine trees (Pinus thunbergii) along the coasts were damaged by salty water driven by the typhoon, but the magnitude of its damages and recovery rates of damaged vegetation varied by species. These results indicate that prediction and proactive activities for salty wind are needed to reduce its damages to local vegetation particularly before the arrival of a dry typhoon accompanying gusty wind.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.88-98
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• 2016

Purpose: We recruited 118 women in their early 20's to examine the relationship between sodium intake and salty taste thresholds and preference. We also examined the association of salty taste preference with sodium-related dietary behaviors and major dishes contributing to sodium intake. Methods: Daily sodium intake was estimated using a 127-item dish-frequency questionnaire. Salty taste thresholds and preference were measured using rating scales using water solution of NaCl and a self-administered questionnaire based on a Likert scale, respectively. Results: Salty taste preference showed positive correlation with daily sodium intake and sodium intake-increasing behaviors, and inverse association with sodium intake-decreasing behaviors, including salt and soy sauce use at the table, the frequency of eating out and home delivery of foods, broth consumption of soup, stew or noodle soup, the use of ready-to-serve or processed foods, fresh vegetable intake, and the accommodating attitude toward bland food. Intake of sodium-contributing dishes, including ramen, spicy soft-tofu stew, radish kimchi, and dishes containing kimchi, also showed positive association with salty taste preference. Unexpectedly, detection and recognition thresholds of salty taste showed no association with salty taste preference, sodium intake, and sodium-related dietary behaviors. Conclusion: These findings suggest that salty taste preference could reflect sodium intake of individuals rather than thresholds of saltiness, and may be used as a simple and effective proxy for usual sodium intake.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.494-503
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• 1995

The selection of salt tolerant rice variety needs an effective method in its testing. Salinity of irrigated water, 0.5% at seedling stage, 0.6% at tillering stage, and 0.9% at panicle formation stage were treated to test salt tolerance of rice using 45 cultivars. At tillering stage, salty water irrigation reduced plant height to 22.6% in early maturing rices(EMR), 30.5% in medium maturing rices(MMR), and 20.9% in medium-late maturing rices(MLMR), and also reduced number of tillers to 11.2% in EMR, 36.2% in MMR, and 36.0% in MLMR compared to rices grown in non-salty water irrigation. At panicle formation stage of rice, salty water irrigation affected plant height and tiller numbers that showed varietal differences. As salt tolerant rice cultivars, Daegwangbyeo, Namweonbyeo, Sinseonchalbyeo, Gyehwabyeo, and Daeyabyeo were selected. Jinbubyeo, Donghaebyeo, and Tamjinbyeo were weak in salty water irrigation.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.1-6
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• 2020

To make an automated system for a salt field, it is necessary to measure the salinity and water level of the evaporation site. In this paper, a method to simultaneously measure the salinity and water level by measuring the buoyancy forces of two fixed buoyancy bodies is proposed. The proposed measurement method measures the buoyancy of the main part and reference part when the measuring device is immersed in the salty water, and simultaneously measures the salinity and water level through the sum and difference of the two buoyancy forces. Since there is no mechanical movement in the measurement of buoyancy, measurement errors and maintenance needs can be reduced in the mudy environment of salt field. By applying the proposed method, we developed a system that can simultaneously measure salinity and water level remotely at the evaporation site of a salt field. Through a measurement experiment using a reference salty water having various levels of salinity, the results of a salinity error of 0% and a water level error of 2mm were obtained, and the effectiveness of the proposed salinity and water level measuring device was verified. When an automated system is constructed using the developed salinity and water level measuring device, labor reduction, work environment improvement, and productivity improvement are expected.

• Journal of Plant Biology
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• v.13 no.4
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• pp.23-31
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• 1970

The rice variety, Kwanok, was reared in the water and land beds and transplanted to the reclaimed soil area, having an average salt concentration of 0.39%. Two levels of the moderate and late season cultures with 4 treatments were used. The K and Si contents of the stem part of land bed seedlings were somewhat smaller, but total carbohydrate remarkably larger, the C/N ratio was accordingly greater than water bed seedlings. The rooting ability of land bed seedlings was vigorous markedly in culture solutions, to which added various concentrations of NaCl, The rooting ability of each seedling water not much declined in theculturing solution of up to 9.4mmhos/cm, (0.6%) of salt concentration, but it was drastically declined in the salt concentration over that. It seemed that the critical salt concentration for the rooting rice plant. The land bed seedlings in each salty condition markedly decreased compared with the water bed seeldings in transpiration rate and it showed a stronger drought resistance and contained a large amount of chlorophyll at transplanting stage, and also showed higher stability of chlorophyll at rooting stage in the salt treatment. The number of panicles, panicle weight, number of grains per panicle and ratio of matured grains of the rice plant grown by the land bed seedlings were much greater and 1,000 grain weight was less than from water bed seedlings. The cultural practices with the land bed seedlings increased the rough rice yields by 15% and 11%, respectively, compared with the yields of the moderate and late season cultures by water bed seedlings.

• Journal of the Korean Home Economics Association
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• v.17 no.4
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• pp.43-47
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• 1979

In order to get taste sensation 116 male and 82 female subjects were tested by dropping solution on tongue. Table I shows the number of subjects in each selected age group. none of the subjects complained gastrointestinal discomforts and drinking and smoking habits were moderate (Less than 5 cigarettes a day). Taste sensation was elicited by applying standard tap water solutions of sucrose(sweet), , sodium chloride(salty), citric acid (sour) and quinine (bitter) on tongue. The dour concentrations of each solution are given in Table 2. The test were done about 1 hour after meal . A drop of approximately 0.1 ml of the lowest concentration of solution was placed on tongue. The number of subjects who recognized the taste of concentrations were recorded in each age group. The obtained results were as follows ; 1. The sweet taste sensation of each age group was more sensitive in female than in male. 2. Decreased level of sensitivity to sweet. salty, sour and bitter taste was detected in the 40 year age group. 3. Females tent to be more sensitive to taste than males generally.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.92-97
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• 2008

Salt wedge into the river from the sea or fresh water flume (fresh wedge) in the ocean from the sea has density current characteristics. However, when temperature and salinity simultaneously determine the density of wedges, one of salinity and temperature can distributed in the reversed profiles against gravity, even though the density profile is stable. In this case, the double diffusive process is critical in determining mixing rate. The present work studies relative contribution of shear driven mechanical mixing component and double diffusive layering process, when warm salty denser water is introduced into the cold fresh lighter water column. Laboratory experiment releases warm salty denser water into cold fresh lighter water controlling discharge amount to achieve the steady state of density current. When longitudinal density rate becomes 15, the released amount ratio of salt and heat changes sharply and in the releasing point, vigorous mixing occurs with increase of discharged amount due to double diffusion. Double diffusion distabilizes gravitational stability and enhances the mixing rate up to $6{\times}10$ times at the lower density ratio comparing to the higher density ratio.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.237-241
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• 2003

The world's supply of water in all forms is enormous. However, only a tiny fraction of the planet's supply is available to us as fresh water, and that is distributed very unevenly. About 97％ of oater volume is found in the oceans and is too salty for drinking, growing crops, and most industrial uses except cooling. In addition water supply crises in already-water-short-regions will intensify because population and industrialization increase. Today, remote monitoring and control systems are becoming the cost-effective management tools for almost all water user groups, including irrigators, water districts, municipal water suppliers, and wildlife management groups. This paper represents a new approach in the water-gate control using radio communication. The proposed device is simple in structure and suitable for implementation of water-gate control through the transceiver by radio communication. It was confirmed that the developed device was very efficient to control level of water-gate and to prove the up and down motion of water-gate through the LCD displayer.

• Journal of Korean Home Economics Education Association
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• v.30 no.4
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• pp.83-91
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• 2018

This study was performed to measure the liquid intake and the liquid intake difference by obesity, exercise frequency, and salty food intake score in female high school students. A total of 235 students in Daejeon area were participated, and the liquid intake was recorded for 3-days(2 weekdays and 1 weekend) by self-recording. The T-test, F-test, Pearson's correlation, and Scheffe test were exercised. The results of this study are as follows. The amount of total liquid intake was 838.5 ㎖/d. Among the 13 kinds of beverages, water was the highest 611.6 ㎖/d, 72.9% of liquid intake total, followed by carbonated drink(65.7 ㎖/d), milk(41.6 ㎖/d), fruit drink(32.8 ㎖/d), and fruit·vegetable juice(25.4 ㎖/d). The other beverages' intake were very small, ≤13.0 ㎖/d. Carbonated drink, milk, and coffee's intake were higher during weekend than weekday. There were sig. difference in water and total liquid intake by the obesity, student of BMI≥23.0 was higher than students of BMI<23.0. And only carbonated drink was sig. different by exercise frequency and salty food intake score. Exercise frequency of ≥3 d/week and salty food intake score of ≥7(very dangerous) consumed more carbonated drink than the lower counterparts. Total liquid intake of female high school students was not reach to 900 ㎖/d, the Adequate Intake in Dietary Reference Intake for Koreans 2015. The amount of milk intake was 41.6 ㎖/d, far less than the Recommended Intake of 2 serving, 400 ㎖/d. Education and promotion program may necessary to increase the liquid intake amount and to choose the nutritious beverage.