• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.636-641
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• 2017

Water is an essential resource for human survival. According to the OECD Environmental Outlook to 2050, rapid industrialization and a global population increase by approximately two billion will likely increase global water use by 55% in 2050. However, water depletion has been getting worse than before and has been happening more quickly, as Earth's water resources are limited. The present study proposes water management measures by using the virtual water theory which enables water consumption measurement and the confirmation and recognition of water scarcity problems, and will support the development of counter-measures. As a method for estimating the value of agricultural water, virtual water theory was used to calculate the amount of agricultural water input for domestic rice and to apply prices of agricultural water in the United States and China to Korean water prices. When the Chinese price was applied to Korean water prices, the value of agricultural water represented 0.3% of the Korean rice producer's price. When the US price was applied to Korean water prices, the value of agricultural water represented 1.6% of the domestic rice producer's price. The study exposes the percentage of the value of agricultural water in agricultural product prices, as well as how this scare resource may affect future prices. In the future, if there are water charges to effectively manage agricultural water, this study, which uses the virtual water theory, can be used as a preliminary research.

• Journal of environmental and Sanitary engineering
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• v.16 no.2
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• pp.56-62
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• 2001

This study is carried out to investigate the water quality changes in Busan Metropolitan streams, The results are as follows. The level of organic contaminants($BOD_{5}$ and $COD_{Mn}$) is found to be low and does not show seasonal variation in domestic waste water streams. But, the level of organic contaminants in industrial waste water streams is relatively high and seems to be seasonally variable, which is affected by other factors. The nutrient materials, such as nitrogen(as T-N, about 20mg/L) and phosphorus(as T-P about 2.0mg/L), are abundant than Nak Dong River and the general trends of contaminants level are similar to those of organic contaminants. The chronic water qualities, including organic, nutrient contaminants levels, show that the loading rates in 1998 are smaller than the past(1983, 1992). And this trend is more evident in industrial waste water streams than domestic waste water streams.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.156-161
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• 2004

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar hot water heater with high efficiency has been used for the house and the industrial process on business, advanced nations were reached up the experimental stage of solar generation system. But, the actual circumstance of the domestic has been not accomplished the popularization of solar hot water heater and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar hot water heater, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar hot water heater, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid for the enlargement and the popularization on solar energy.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.865-870
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• 2009

In this study, the adequacy of Reynolds numbers and Froude numbers derived from about sixty domestic water treatment plants (WTPs) were analyzed in order to estimate the characteristics of hydraulic behavior within the rectangular shaped sedimentation basins used widely. From the results of analysis, most of domestic WTPs have satisfied the criteria regulated as that Reynolds number should less than 1,000(dimensionless). On the other hand, they have not been able to satisfy the Froude number criteria, which should be higher than $1.0{\times}10^{-6}$. The reasons why most of domestic WTPs could not satisfy the criteria are that its criteria basis has been not only inadequate, but also the concept of external flow occurred around a settling particle has been ignored. Accordingly, this study proved the feasibility of Archimedes number, which indicates the ratio between particle Reynolds number and Froude number, to evaluate the hydraulic efficiency and its function of scale factor.

• KIEAE Journal
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• v.4 no.3
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• pp.37-44
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• 2004

In this study, foreign and domestic noise criteria on walls, floors, and water supply facilities were reviewed and the results are as follows : regulation can be divided two things, one is on thickness the other is sound insulation performance. Green Building regulation based on the law and this have sound classification systems. Since these regulations are not established in Korea. The noise regulation on water supply-drain facilities and domestic guideline on interior noise level is needed. Foreign regulations are stricter than those of ours. And those has sound classification system for the better acoustic condition of inhabitants'.

• Solar Energy
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• v.11 no.3
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• pp.84-88
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• 1991

In this technical status report, domestic solar makers and dealers for thermal collectors and hot water heaters are surveyed. The characteristics and specifications of their items are also classified and discussed. Collectors and hot water heaters are the key part of solar thermal systems which have been developed under the national policy for the development and utilization of new and renewable energy resources. This report provides the current domestic status of solar collectors which may be a good reference for the solar industry and related organizations.

• Journal of the Korean Wood Science and Technology
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• v.21 no.2
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• pp.67-72
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• 1993

Hot water extractives of sawdust/particle from domestic and foreign wood species, which were composed of pitch pine, Korean pine, larch, Italy poplar, acacia and oak as Korean wood species, Malaysian oil palm and German spruce were quantitatively analyzed with thin layer chromatography. Sugar components of saccharose, galactose, glucose, fructose and arabinose were contained in these wood species. It was assumed that arabinose and glucose are major inhibitory components against cement hardening in larch and oil palm, respectively, since both species contain a large amount of each sugar. In contrast, fructose might not influence so badly on a cement hardening, when considering that fructose was contained much in Italy poplar with a good cement hardening character. Galactose was a minor component.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.509-516
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• 2014

This study describes a reasonable planning method for water meter replacement which can minimize the metering under-registration for an increasement of revenue water. The increment analysis of real water usage was used to establish a replacement plan. The meter replacement database collected from K City was used as the basis of this analysis. The database included 964 connections of domestic and non-domestic consumers that had their meter replaced by aging at 2011. The result showed that the corelation between unregistered water volume and water meter age was lower than commonly expected where the current criteria of replacement is only water meter age(8 years) excluding the meters older than 13 years. And in the analysis result of water usage for 8 years, the total amount and increment of water usage had a significant effect on unregistered water volume. However the relation was different tendency as a total volume and slope of increment. In case of total water volume was larger than 10,000, larger than 7,000 and increment of 0.0 ~ -0.3, larger than 6,000 and increment more than -0.3 were analysed to need a replacement because of metering under-registration.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.509-518
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• 2006

Although final water of domestic water treatment plants almost contains highly corrosive characteristics, the countermeasures for eliminating internal corrosion of pipeline system have not been conducted yet by controlling water quality in plants. The technologies of internal corrosion control are to control water quality parameters(pH, Alkalinity, and Calcium Hardness etc.) and to use corrosion inhibitor. Under the conditions of domestic water treatment, first of all, the technologies of adjusting water quality parameters has to be considered. Otherwise, The technology of using corrosion inhibitor is favorably thought to be applied with the technology of adjusting water quality parameters in accordance with the result of availability for water treatment process. Since the technology of adjusting water quality parameter influences on other water treatment processes, the guideline of water quality management to be apt for water quality characteristic is required to be estabilished. While the selection of proper chemicals and technologies is dependent upon the raw water characteristics and water treatment process, typically, the technology of $Ca(OH)_2$ & $CO_2$ additions is considered more effective than other technologies in order to adjust pH and Alkalinity, increase $Ca^{2+}$ and form $CaCO_3$ film

• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.15-23
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• 2013

In this study, thermodynamic performance of R435A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 20%R152a/80%RE170 using actual domestic water purifiers. This mixture is numbered and listed as R435A by ASHRAE recently. Test results show that the system performance with R435A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R435A is 11.8% lower than that of HFC134a. The compressor discharge temperature of R435A $8^{\circ}C$ lower than that of HFC134a at the optimum charge. Overall, R435A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.