• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.497-502
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• 1990

The effect of sugar concentration, immersion time and temperature on water loss, solid gain or loss, and sugar molality of potatoes during osmotic concentration was analyzed by a response surface methodology (RSM), and those values were predicted by using a second degree polynomial regression model. Effect of osmotic concentration and blanching on vitamin C retention of air dried potatoes (6% MC: wet basis) was also evaluated. The most significant factor was sugar concentration for water loss, solid gain or loss, sugar molality, rate parameter and retention of vitamin C. Second and third factors were immersion time and temperature respectively. Water loss and solid gain were rapid in the first 10 min and then levelled off. A 44.6% of water loss was observed during osmotic concentration using a sugar solution $(60\;Brix,\;80^{\circ}C$) with 20 min of immersion time. Dried potatoes after osmotic concentration had higher vitamin C content than dried potatoes after blanching. Optimum regions for osmotic concentration process of potatoes were $60-70^{\circ}C$ of immersion temperature, 60 Brix of sugar solution and 16-20 min of immersion time based on above 30% of water loss and 50% of vitamin C retention.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.159-166
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• 2007

Large scale flood disasters bring human losses and properties, which lead to the decrease of our productive value and change social environment. Human loss and economic damage are considered to be the same system but they are viewed as separated systems. The total amount of human loss can be represented as the total amount of economic damage estimated in the frame of social system while it will be possible to make mutual changing by clearing the relations between social and economic systems. In this regard, an attempt to estimate economic loss considering per capita Gross Domestic Production (GDP) caused by flood-related mortality was carried out to the typhoon Rusa of 2002 in Kangwon-do. The proposed method tried to capture quantitative factors which are affecting the loss of per capita GDP. The approach has great importance not only to set up governmental policy but also methodological progress in the research due to impact of disaster-related mortality on GDP loss.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.45-50
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• 2005

Agricultural water is the main portion of water resources in Korea. And water loss of agricultural water is estimated 6% of all water resources. But studies and data for water loss aren't sufficient. We classified the agricultural water losses and measured the water losses in 6 experimental site. Measurements says that water losses ratio in main canal is 13.8%, water losses for distributing irrigation water is 31.1%. So, the total water losses is about 45%. But the water losses for distributing irrigation water is imperative factor for irrigation, So, it is not right that the water losses for distributing irrigation water is classified water losses and it is necessary to reclassify the agricultural water losses.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.8-12
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• 2022

Water loss is one of the typical but challenging problems in water management. To reduced water loss or increase water efficiency, the pilot projects were implemented in the TTD's irrigation area. Modern soil moisture technology and local level water user training were conducted together as a mean to achieve improved water efficiency. In terms of technology, soil moisture sensors and monitoring system were used to estimate crop water requirement to reduce unnecessary irrigation. This was found to save 16.47% of irrigated water and 25.20% of irrigation supply. Further improvement of water efficiency was gained by means of local level water user training in which stakeholders were engaged in the network of communications and co-planning. The lessons learnt from the TTD pilot project was translated into good water management practices at local level.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.270-276
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• 2006

In this study, heat loss through free surface of water contained in bathtub due to conduction and evaporation has been analyzed. As a result of this study, a relational equation has been derived based on the basic theory of heat transfer to evaluate the performance of bath tubes. The derived equation was rational and quantitative. The major heat loss was found to be due to evaporation. Moreover, it has been found out that the speed of heat loss depends more on the humidity of the bathroom than the temperature of water contained in the bathtub. So, it is best to maintain the temperature of bathtub water to be between 41 to $45^{\circ}C$ and the humidity of bathroom to be 95％.

• Membrane and Water Treatment
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• v.13 no.6
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• pp.313-320
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• 2022

Theoretical calculation results are presented for the enhancement of the water mass flow rate through the hydrophobic micro/nano pores in the membrane respectively on the micrometer and nanometer scales. The water-pore wall interfacial slippage is considered. When the pore diameter is critically low (less than 1.82nm), the water flow in the nanopore is non-continuum and described by the nanoscale flow equation; Otherwise, the water flow is essentially multiscale consisting of both the adsorbed boundary layer flow and the intermediate continuum water flow, and it is described by the multiscale flow equation. For no wall slippage, the calculated water flow rate through the pore is very close to the classical hydrodynamic theory calculation if the pore diameter (d) is larger than 1.0nm, however it is considerably smaller than the conventional calculation if d is less than 1.0nm because of the non-continuum effect of the water film. When the driving power loss on the pore is larger than the critical value, the wall slippage occurs, and it results in the different scales of the enhancement of the water flow rate through the pore which are strongly dependent on both the pore diameter and the driving power loss on the pore. Both the pressure drop and the critical power loss on the pore for starting the wall slippage are also strongly dependent on the pore diameter.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.669-676
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• 2016

A field study was conducted to determine the runoff loss of N and P in small scale of red pepper field plots (10% slope), consisting of three different plots with black polyethylene vinyl mulching (mulching), ridge without mulching (ridge), and flat without ridge and mulching (flat). Composted manure and urea as a basal application were applied at rates of $20MT\;ha^{-1}$ and $93kg\;N\;ha^{-1}$, respectively. Urea at $189kg\;N\;ha^{-1}$ and fused phosphate at $67kg\;P_2O_5\;ha^{-1}$ were additionally applied on June 25 with different fertilization methods, broadcast application in flat plot and hole injection in ridge and mulching plots. Plant uptake of N and P was positively correlated with their respective concentrations in surface soil: mulching > ridge > flat plots. The runoff loss by soil erosion was higher in flat plot than ridge and mulching plot with contour line. Nitrate loss by the runoff water had no significant differences among three surface management practices, but the higher average value in ridge and mulching plots than flat plot. Especially, the flat plot had no phosphate loss during summer season. This is probably due to low labile P content in surface soil of flat plot. In the summation of soil and water loss, flat plot was higher in N and P loss than ridge and mulching plot with contour line. Nevertheless, the nitrate and phosphate loss by runoff water could be more important for non-point source management because the water could meet the river easier than eroded soil because of re-deposition around slope land.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.86-97
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• 2005

Nowadays, Water Mist Fire Extinguishing System is increasingly used in maritime field for various application. The fire extinguishing capability of the system should be verified by hydraulic calculation in the same manner as the conventional water based fire extinguishing system such as sprinkler system. water spray system and etc. Additionally, the review of effectiveness of friction loss calculation method used for hydraulic calculation is needed because the pipe flow characteristic of its piping system has higher Reynolds number than that of the conventional system. In this paper the review work was carried out based on the NFPA Code 750.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.445-451
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• 2019

This paper presents the design of a water-cooled radio-frequency(RF) load with simple structure, for use in the ultrahigh-frequency (UHF) band. After establishing a formula to obtain the physical properties that affect RF matching, we measure the permittivity and $tan{\delta}$(Loss tangent) of tap water. Because the temperature of tap water increases upon applying high power, we measure the permittivity and $tan{\delta}$ for all changes in the temperature of tap water. In order to reduce the length of the water-load, molybdate with high $tan{\delta}$ is mixed with tap water. The loss tangent of the mixture is found to be approximately 26 times higher than that of tap water. Finally, we manufacture a water-cooled RF load and measure its characteristics. A reflection coefficient of -19 dB and bandwidth of 15 % is obtained at 460 MHz.

• 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.