• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.95-101
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• 2011

We estimated on the stability of W/O type emulsified fuel using by capacitance sensor, so it concluded the following conclusions. For the first 24 hours, prepared emulsified fuel reveals phase separation ratio of 5%, maintains stable status which verifies the stability of emulsified fuel. Adding more water increases the phase separation ratio rapidly, and adding more surfactant displays stable emulsification. Adding water causes larger size of water droplet diameter, and adding surfactant mixture causes smaller size of water droplet diameter. In conclusion, the size of W/O type emulsified fuel water droplet diameter is directly related to the volume of surfactant, and density of water droplet diameter changes thedistribution according to water contents.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.297-316
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• 1996

This research emphasizes the necessity of the understanding and cooperation among focal governments to preserve the water quality of the Nak-dong river that runs through four local governments. First, this research considers the status of water-pollution in the Nakdong river, describes and finds problems within the central government's. "Clean Water Supply Plan" and local governments' water quality-related policies. Second, it deals with the conflict among local governments concerning the planning and building of "Wicheon Industrial Complex" in the middle-upstream of the Nakdong river which has triggered the opposition movement of the local governments and residents of the river's downstream area. With stressing the necessity of the understanding and cooperation among local governments, this research emphasizes roles of central government, of academic experts, and of local news-media in preserving the water quality. Key words : the Nakdong river, water quality policy, the conflict among local governments, the activation of local autonomy, Wicheon Industrial Complex, the cooperation among local governments.

• Toxicological Research
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• v.18 no.2
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• pp.107-116
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• 2002

Arsenic (As) is a ubiquitous element found in several forms in foods and water. Although certain foods, such as marine fish, contain substantial levels of organic arsenic forms, they are relatively low in toxicity compared to inorganic forms. in contrast, arsenic in drinking water is predominantly inorganic and highly toxic. Chronic ingestion of arsenic-contaminated drinking water is therefore the major pathway posing potential risk to human hearth. since the early 1990s in Bangladesh ozone, arsenic exposure has caused more than 7,000 deaths and uncounted thousands shout symptoms of long-term arsenic poisoning. Significant portion of world populations are exposed to low to moderate levels of arsenic of parts per billion (ppb) to hundreds of ppb. As a consequence, the World Health Organization (WHO) and U.S. environmental health agencies, such as the Environmental Protection Agency (EPA) made arsenic their highest priority. Recently, the WHO, European Union (EU), and US. EPA lowered an acceptable level of 10 ppb for arsenic in drinking water In this article, various health effects of arsenic in drinking water were reviewed and the current status for risk assessment to regulate arsenic in drinking water was discussed.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.11-20
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• 2014

This research examined the effect of the quality of aggregate on concrete workability and compressive strength through an investigation into regional aggregate used in domestic ready mixed concrete plants. Through the research, it was found that aggregate for ready mixed concrete shows poor quality overall. The main factor of deterioration in the quality of the concrete is the particle size of fine aggregate and fine particle content in coarse aggregate. The quality of aggregate significantly influences concrete's workability, which is defined based on 0.08mm passage related with powder and absorption. In addition, poor aggregate quality leads to increased water content in concrete to secure workability, which is related with a decline in the compressive strength and durability of concrete.

• Journal of Nutrition and Health
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• v.4 no.3
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• pp.13-25
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• 1971

During a period from October 1st to November 15th in 1971, We made a survey on hygienic status of kitchen utensils used at 270 college student's home in 9 districts of Seoul city. The results obtained could be summarized as follows. In bacteriological study on the kitchen utensils 20.7% of them revealed contaminations with general bacterial counts of over 100/m1 and 20.0% of them with coliform bacteria. It was probable that degrees of bacterial contamination of the kitchen utensils were chiefly attributable to levels of education of housewives and living standard of individual household. Factors that were presumed to be directly responsible for the contamination were sources and storage of water and methods of washing the utensils. One of the major sources of contamination was derived from the use of a piece of cloth (Hangjoo) to wipe up the utensils after soashing. Hygienic treatment of Hangjoo in urgently needed. Otherwise, it is desirable not to used the Hangjoo and leave the utensils dry after washing them with boiling water.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.7-13
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• 2005

There are two ways to mitigate the drought. One is the structural measures such as storage of irrigation water, development of emergency wells, etc. The other one is the nonstructural measures such as water saving management by the early warning system. To precast and evaluate the drought, we need to develop the drought indices for agriculture. In the present drought preparedness plans of Ministry of Agriculture and Forestry (MAF), it is prescribed that the preparedness levels should be classified by considering the precipitation, reservoir storage, soil moisture in paddy and upland, and the growing status of crops. However there are not clear quantitative criteria for consistent judgment. This shows that we have not selected and utilized the proper drought index for agriculture and we did not have the information system to calculate the drought indices periodically and warn the outbreak of the drought. The objectives of the study are to develope of Agricultural Drought Evaluation System and to evaluate this indices for current agricultural status using the system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.1-7
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• 2004

The purpose of the study is to review current status of green roof technology and to suggest the issues and solutions related with the technological problems of green roof in Korea. The scope of the study is limited to the extensive green roof which requires low maintenance. Technological issues related with green roof include soil, water proofing, water drain, vegetation and maintenance. Several solutions to invigorate green roof technology were suggested as follows; 1)implementation of technical standard for green roof and technology certification system, 2) development of suitable raw materials for green roof, 3) construction guidelines and uniform construction specification, 4) formulation of city ordinance for green roof, and 5) exchange program with foreign green roof organizations.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.153-158
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• 2008

Artificial reef in Thailand was trend to deploy and development artificial reef program to enhancing fisheries product and also use artificial reef for solve coastal problem. Artificial reef in Thailand was present in type of shallow water artificial reef by use concrete dice as dominant structure. To development artificial reef program for more benefit such as deep water artificial reef program that might provide more fisheries product for commercial fisheries and apply for use in many purposes especially for manage coastal environment in Thailand can be suggestion by cases of study. But all of that have to use more knowledge and concerning from government and organization that was responds in artificial reef program to decide the future of artificial reef program in Thailand.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.76-86
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• 2023

We are on the verge of paradigm shift for the design and operation of our urban water systems from treatment- and efficiency-based to recirculation- and sustainability-based. One of the most frequently suggested alternatives to embody this paradigm shift is to decentralize the currently highly centralized urban water infrastructure. However, claims for water infrastructure decentralization are often criticized due to poor economic feasibility, unstable performance, and unprofessional operation and maintenance. The current study critically reviews the literature to discuss the technical advancement needs to overcome such challenges. Firstly, decentralized water infrastructure was briefly defined and the rationale for the proposal of its introduction to the next-generation urban water systems was laid down. The main discussion focused on the following water technologies, which require special attention when working with decentralized water infrastructure: i) material collection, storage, and transport; ii) easily scalable water treatment; iii) sensor, information, and communications; and iv) system optimization. The principles, current development status, and challenges were discussed for each of the water technologies. The discussion on the water technologies has enabled the identification of future research needs for their application to the next-generation urban water systems which will be designed following decentralized water infrastructure. This paper will significantly improve the current understanding on water infrastructure decentralization and provides insight on future direction of water technology development.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.365-368
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• 2002

In spite of considerable advances in water quality control measures within lake, many basic questions concerning an eutrophication still remains unanswered and it becomes obvious that an extensive limnological database is needed for the inter-comparison between bodies of water and for the assessment of the status of lake water quality. In order to diagnose the water environment and assess the changes of the water quality, Wangkung irrigation reservoir was investigated by a long-term monitoring program for the physical, chemical and biological water quality parameters. In addition, these data was used to determine the design elements of natural purification facilities.