• Journal of Nutrition and Health
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• v.50 no.2
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• pp.121-132
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• 2017

Purpose: This review was performed to establish a reference intake of water for Korean (KDRI-water) adults in 2015 by examining current knowledge of the relationship between water intake and health and the general status of water intake and loss. We expect that this study will be utilized for further refinement of KDRI-water. Methods: Documents were searched using RISS, NDSL, DBPIA, CINAHL, and Pubmed with the keywords 'water intake, water supply, water ingestion, hydration, dehydration, water balance, and fluid balance'. Results: Water balance is essential for the maintenance of health. Based on this assumption, numerous studies have been performed to investigate the association of water intake with several diseases such as urolithasis, obesity, diabetes, and cancer as well as other health problems, including constipation, cognition, and fetal weight. Effects of water intake for prevention or relief of these health problems vary. Water is supplied to the body by eating foods and drinking liquids such as plain water and beverages. Metabolic water is another source of water input. Water is lost through urine, skin, respiration, and feces. KDRI-water 2015 was set by adequate intake (AI) based on water intake volume, which was the sum of water intakes from foods and fluids reported by the Korea National Health and Nutrition Examination Survey, with extra milk intake of 200 mL. AIs in some age groups were modified considering their estimated energy requirements. Conclusion: Accurate data of water intake is critically important for the establishment of KDRI-water. Therefore, improvement of systems investigating water intake is required, and more studies on the status of water intake and loss in Korean people are needed for definite KDRI-water establishment.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.430-440
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• 2021

This study was conducted to investigate the intake status of beverages and water in Korean adults using data from the 8th National Health and Nutrition Examination Survey. The 'total water' intake was 2,250.6 g for men and 1,871.2 g for women. Men and women consumed an average of 314.9 g of 'total beverages', of which 'coffee' was the largest at 107.5 g, followed by 'others'(65.4 g), 'milk' (44.8 g), 'soda' (44.1 g), 'teas' (20.9 g), and 'fruits and vegetables' (18.5 g). The intake of 'plain water' was 1,059.9 g, and the intake of 'water from food' consumed was 547.3 g. The 'total water' intake decreased with increasing age in males and females (p<0.001). Both men and women showed a tendency toward increased 'total water' intake as income levels increased. 'Plain water' intake accounted for 51.4% of the 'total water' intake in males and females. The intake of all nutrients significantly increased from the Q1 group to the Q4 group by quartile ranges of total water intake. The results of this study showed that the intake of healthy water should be considered, and care and educational programs are needed, especially for older people, to ensure adequate water intake.

• Nutrition Research and Practice
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• v.8 no.5
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• pp.580-588
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• 2014

BACKGROUND/OBJECTIVES: The objective of the study was to provide useful insights into plain water intake of Korean adults according to life style, anthropometric, and dietary characteristics. SUBJECTS/METHODS: The data from the 2008-2010 Korea National Health and Nutrition Examination Survey were used. The subjects were 14,428 aged 20-64 years. Water intake was estimated by asking the question "How much water do you usually consume per day?". Dietary intake was estimated by 24-hour dietary recall. A qualitative food frequency questionnaire including 63 food items was also administered. RESULTS: The mean plain water intake for men and women were 6.3 cup/day and 4.6 cup/day, respectively. Plain water intake increased as lean body mass, waist circumference, and body mass index levels increased, except for percentage of body fat. As energy and alcohol intakes increased, plain water intake increased. As total weight of food intake and total volume of food intake increased, plain water intake increased. Plain water intake increased as consumption of vegetables increased. Plain water intake increased as frequencies of green tea, alcoholic drink, and all beverages were increased in men. Plain water intake increased with increased frequencies of green tea, milk, soy milk, and alcoholic drink and decreased frequencies of coffee and soda in women. CONCLUSIONS: Our results suggest that persons who had a higher waist circumference or lean body mass and women with higher BMI consumed more plain water. The persons eating high quality diet, or the persons who had more vegetables, green tea, milk, soy milk, or alcoholic drink consumed more plain water.

• Journal of the Korean Solar Energy Society
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• v.29 no.2
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• pp.31-38
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• 2009

This study was conducted to forecast inner water temperature strata change by extracting deep water from a dam. For the methodology, the scope wherein the balance between the volume of low-temperature water intake through the virtual water intake opening as installed within the stored water area and the volume of water intake from the surrounding area is not destroyed was calculated through the CFD simulation technique using the computational fluid dynamics(CFD) interpretation method. This study suggested a supplementary method(diffuser) to avoid destroying the water temperature strata, and the effect was reviewed. In case of intake of the same volume, when the velocity of flow of water intake is reduced by increasing the pipe diameter, the destruction of water temperature strata can be minimized. When the area(height) where the intake of water is possible is low, a diffuser for interrupting the vertical direction inflow should be installed to secure favorable water intake conditions in case of water intake on the upper part. This study showed that there was no problem if the intake-enabled, low-temperature area was secured approximately 10m from the bottom when the scope that does not destroy the water temperature strata in case of water intake was forecast using the regression formula.

• Korean Journal of Community Nutrition
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• v.24 no.1
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• pp.18-23
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• 2019

Objectives: Although water is essential for life and can supply essential minerals, studies that evaluate calcium intake through drinking water are limited. The aim of this study was to assess calcium contents of natural mineral water (NMW) and its possible contribution to calcium intake in healthy adults. Methods: This study examined water consumption in 640 Korean adults with self-selected diet, analyzed the calcium content of 10 different brands of bottled NMWs sold in Korea, and assessed the amount of calcium intake from drinking water and its daily contribution to the recommended nutrient intake (RNI) of calcium. Results: Mean calcium content in 10 bottled NMWs was 20.9 mg/l. Daily water intakes from food composition database and calculated using energy intake based on 0.53 ml/kcal were 957.2 ml and 1109.8 ml for men and 848.3 ml and 951.6 ml for women, respectively, with a significant difference by gender (p<0.001). Daily drinking water intake was significantly higher among men than women (1203.9 ml vs. 1004.3 ml, respectively, p<0.001). Daily calcium intakes from foods were 564.0 mg for men and 534.2 mg for women. Daily possible calcium intakes from drinking bottled water were 25.2 mg for men and 21.0 mg for women (p<0.001). The contribution of daily calcium intake from drinking bottled water to RNI of calcium was 3.3% for men and 2.9% for women without significant difference. Conclusions: One half of the daily total water intake was consumed as drinking water, and possible calcium intake through drinking water was about 3% of RNI.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.32-37
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• 2005

Under a typical Mediterranean environment in southern Australia, the evaporation rate increases significantly in hot summers, resulting in highly saline drinking water for grazing animals. Also in the cropping areas, dryland salinity is a problem. Grazing animals under these environments can ingest excessive amount of salt from feed, drinking water and soil, which can lead to a reduction in growth rate. To understand the impact of high salt intake on grazing deer, two experiments were conducted to assess the effect of salt levels in drinking water on feed intake and growth rate of red and fallow weaner deer. The results revealed that fallow deer did not show any abnormal behaviour or sickness when salt level in drinking water was increased from 0% to 2.5%. Feed intake was not affected until the salt content in water exceeded 1.5%. Body weight gain was not affected by 1.2% salt in drinking water, but was reduced as salt content in water increased. Compared with deer on fresh water, the feed intake of red deer on saline water was 11-13% lower when salt level in drinking water was 0.4-0.8%. An increase in salt level in water up to 1% resulted in about a 30% reduction in feed intake (p<0.01). Body weight gain was significantly (p=0.004) reduced when salt level reached 1.2%. The deer on 1% salt tended to have a higher (p=0.052) osmotic pressure in serum. The concentration of P, K, Mg and S in serum was affected when salt level in water was over 1.0%. The results suggested that the salt level in drinking water should be lower than 1.2% for fallow weaner deer and 0.8% for red weaner deer to avoid any reduction in feed intake. Deer farmers need to regularly test the salt levels in drinking water on their farms to ensure that the salt intake of grazing deer is not over the levels that deer can tolerate.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.74-80
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• 2014

Water is essential for life and plain water instead of sugar-sweetened beverages is one approach for decreasing energy intake. Due to limited data on characteristics associated with water intake among Korean adolescents, this study examined associations of demographic and behavioral characteristics with plain water intake by using nationally representative sample of South Korean adolescents. The data (2007-2010 Korea National Health and Nutrition Examination Survey) for 1,288 high school-aged adolescents (15-18 years) were used. Multivariable logistic regression was used to calculate adjusted odds ratios (OR) for factors associated with low water intake (< 4 cups/day) and very low water intake (< 2.5 cups/day). Nationwide, 38.4% and 19.0% of adolescents reported drinking water < 4.0 cups/day and < 2.5 cups/day, respectively. The mean plain water intake was 5.7 cups/day for males and 4.1 cups/day for females. Females had significantly higher odds for drinking water < 2.5 cups/day (OR = 2.2) than males, whereas adolescents with low milk consumption had significantly lower odds for drinking water < 2.5 cups/day (OR = 0.7). Factors significantly associated with a greater odds for drinking water < 4 cups/daywere being female (OR = 2.8) and not meeting physical activity recommendations (${\geq}20$ min/day on < 3 days/week) (OR = 1.6). Being underweight, overweight, and obese were significantly associated with reduced odds for drinking water < 4 cups/day (OR = 0.7, 0.4 and 0.5, respectively). However, intake of soda, coffee drinks, fruits, vegetables, and sodium and eating out were not significantly associated with low or very low water intake. These findings may be used to target intervention efforts to increase plain water intake as part of a healty lifestyle.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.393-399
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• 2017

In order to determine the optimal water intake point, the distribution of blue-Green algae and water quality factors in relation to the depth of the Mulgum and Maeri stations located downstream of the Nakdong River were investigated from Jun. 2015 to Sep. 2016. When the current surface water intake system was converted to the deep water intake system, Chl-a concentration and blue-Green algae were reduced by 64.1% and 80.5%, respectively. Microcystin-LR was reduced by 50% to 100%, while geosmin and 2-MIB of the odorant substances were reduced by 42.9% and 11.8%, respectively. The water quality factors such as pH, water temperature, TOC and COD were gradually decreased by 30% in deep water. Therefore, if we used the deep water intake system selectively in the summer season when blue-Green algae masses occur, the concentration of the influx of blue-green algae and its by-products can be expected to decrease, leading to reduced operation costs in tap water production and improved of raw water quality.

• The KSFM Journal of Fluid Machinery
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• v.13 no.6
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• pp.63-70
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• 2010

Shallow water withdrawal systems have been replaced with a selected withdrawal system to keep stable raw water quality in spite of occurrence of algae and muddy inflow. Before reconstruction of the water intake tower in Yongdam reservoir supplying water to Gosan water treatment facility, we have predicted flow patterns of inflowing water into the water intake tower for various withdrawal conditions. It has been predicted that the water in the withdrawal layer is significantly inflowed from the front with fast velocity into the water intake tower irrespective of withdrawal depth, while the water away from the withdrawal layer is withdrawed a little from the side with slow velocity.

• Environmental Engineering Research
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• v.15 no.4
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• pp.231-237
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• 2010

With increased chemical and economic development activities in upstream areas, the amounts of pollutants released have increased, and as such, so has the need for positive management of water supply source areas. Although more than 90% of the water supply sources in Korea depend on direct intake from surface water, the interest in indirect intake, such as riverbank filtration water, has recently risen, with some local governments currently undertaking indirect intake. Even in cases of indirect intake, water supply source protection zones need to be assigned for the comprehensive control of pollutants. To establish water quality protection zones for indirect intake, the scope of the protection zones needed to reflect the hydrological features of the water-bearing deposits of each site. Water source protection areas were estimated and presented as the 1st (within a 100 m radius from an intake well) and 2nd (within a 2 km radius from an intake well) zones. The 1st zone was more sensitive; hence, the installation of various facilities should be prohibited, and the area should be regarded as off-limits. For the 2nd zone, appropriate management should prohibit and restrict activities already present in the water source protection zone.