• Title/Summary/Keyword: water-related problems

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Present status and effective control measure of water-borne infectious diseases in Korea (수인성 전염병의 현황 및 효율적 관리)

  • 김호훈
    • Journal of environmental and Sanitary engineering
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    • v.9 no.2
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    • pp.41-49
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    • 1994
  • Water- borne infectious diseases can be acquired by contact with contaminated water or by ingestion of contaminated water. There are many water- borne infectious agents such as bacteria, virus, and parasite. Among many of water- borne infectious diseases, health authorities of Korean government has particularly intensified to prevent and control typhoid fever(class I ), shigellosis(class I ), cholera(class I ), paratyphoid fever(class I), amebiasis(class II ) and leptospirosis(euivalent to class II ) under the communicable disease control law. Water- borne disease Prevention and control guideline itself has been also well provided by the health authorities. However, in practical public health point of view, there are still many problems remained to be solved out; no prospective investigation project to survey water borne infectious diseases under the national disease prevention and control programmes, incredible statistic data of annual notifiable disease report frequent appearance and varieties of drug resistance water- borne infectious agents, little cooperation and information- exchange system in between the related government authorities( the health authorities, the environment sanitation authorities and the food hygiene authorities) which should be closely collaborated, lack of health consciousness of the people, necessity of evaluation and Hndification on to the outcomes of performed health activities and programmes, neglect activities for water quality investigation, shortage of expertise and human resources in the related field, and poor investment of the government budget to develope and improve public health and sanitation field. In order to prevent and control water- borne infectious diseases effectively, it is emphasized that all the above indicated should be considered and performed to improve under the national health and sanitation development programmes.

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Mechanical Properties of Cement Paste with Nanomateirals (나노재료를 혼입한 시멘트 페이스트의 역학적 특성)

  • Choi, Ik-Je;Kim, Ji-Hyun;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.193-194
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    • 2020
  • Recently, as the use of high-performance concrete has become common, various problems related to high-performance concrete have become an issue. Among them, self-shrinkage of cement paste due to low water cement ratio is known to cause problems in the volume stability of concrete. To improve this, studies related to the mixing technology of cement-based materials and nano materials have been actively conducted. Looking at the results of prior research related to nano material mixing technology, generally, research results have been reported in which nano materials are incorporated into cement-based materials to improve material properties1). Among them, it was shown that the mechanical performance and various types of functionality of the cement composite are expressed. Among nano materials, carbon nanotubes (hereinafter referred to as CNTs) and graphenes are used in a mixture with cement-based materials. Accordingly, this study intends to compare the mechanical properties by incorporating various CNTs and graphene into cement paste.

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A Study for Developing the Thermal Dehydrator (고효율 열 탈수장치 개발에 관한 연구)

  • Lee, Jung-Eun
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.2 s.23
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    • pp.35-40
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    • 2004
  • A generation rate of sludge in Korea had increased dramatically about $200\%$ for a decade. A requirement for high efficiency dewatering system being possible to produce the low water content cake have suggested due to the appearance of commercial and social problems about handling of dewatered cake. The conventional dewatering system with mechanical compression device was not suitable to produce the low water content cake and didn't cope with lots of requirements. Therefore, this paper was to develop the high efficient filter press with the compressive and heating forces through the heating plate to be built between membrane fillet plates. It is possible to produce the low water content cake and improve the dewatering rate, so this equipment positively coped with several types of problems related to the sludge dewatering. The plate heated by heat transfer materials such as steam, hot water and thermo-oil made the sludge make the residual moisture within the cake to discharge easily and to improve the dewatering efficiency of equipment. The pilot scale experiment with 500kg of cake production showed that the dewatering efficiency determined by the final water content and dewatering velocity was improved $30\%$ more than the conventional dewatering equipment.

A Study on Water Network Modeling System Based Upon GIS (지리정보시스템 기반의 상수관망 모델링 시스템 연구)

  • Kim, Joon-Hyun;Yakunina, Natalia
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.315-321
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    • 2010
  • ArcView and water network models have been integrated to develop the water network modeling system based upon GIS. To develop this system, pre, main, and post processing systems are required. GIS programming technique was adopted by using the ArcView's script language Avenue. The input data of models have been prepared by using the AutoCAD Map3D through the conversion of modeling input data to GIS data for A city. The modeling has been implemented by using EPANET, WaterCAD, InfoWorks. To develop the post processing system, the modeling results of the water network models have been analyzed by using GIS. During the application process of the developed system to B city with 300,000 population, main problems were found in the constructed GIS DB of that city. Thus, pilot study area of B city has been constructed, and pre-, main, and post-processing techniques were invented based upon GIS. Finally, the problems related to waterworks GIS projects in Korea were discussed and solutions were suggested.

A Study for Developing the Thermal Dehydrator (고효율 열 탈수장치 개발에 관한 연구)

  • Lee, Jung-Eun
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.278-283
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    • 2003
  • A generation rate of sludge in Korea had increased dramatically about 200 % for a decade. A requirement for high efficiency dewatering system being possible to produce the low water content cake have suggested due to the appearanceof commercial and social problems about handling of dewatered cake. The conventional dewatering system with mechanical compression device was not suitable to produce the low water content cake and didn'tcope with lots of requirements. Therefore, this paper was to develop the high efficient filter press with the compressive and heating forces through the heating plate to be built between membrane filter plates. It is possible to produce the low water content cake and improve the dewatering rate, so this equipment positively coped with several types of problems related to the sludge dewatering. The plate heated by heat transfer materials such as steam, hot water and thermo-oil made the sludge make the residual moisture within the cake to discharge easilyand to improve the dewatering efficiency of equipment. The pilot scale experiment with 500kg of cake production showed that the dewatering efficiency determined by the final water content and dewatering velocity was improved 30% more than the conventional dewatering equipment.

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Estimation of Optimum Conditions for Controlling scale Problems in Papermaking Process (제지공정의 Scale 제어를 위한 최적조건 규명)

  • 권오철;조병묵;오정수;홍상의
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2001.11a
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    • pp.87-94
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    • 2001
  • Scale is agglomerate or thin film compounded of soluble salts in papermaking process. It causes many problems such as closing up pipelines, contaminating wire and felt, decreasing efficiency of additives and paper quality. In this study, physical factors related to forming scale in white water are determinated and optimum conditions are proposed. To control scale, ACP(Acrylacid Copolymer) was synthesized and compared with conventional chemicals such as EDTA, DTPA and STPP.

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WATER RESOURCES POLICY AND CONFLICT RESOLUTION IN SOUTH KOREA : WIN-WIN STRATEGY

  • Choi, Yearn-Hong;Lee, Tae-Sam
    • Water Engineering Research
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    • v.2 no.4
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    • pp.231-241
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    • 2001
  • Since South Korea has uneven rainfall and deteriorating water quality, it is imperative to create a comprehensive water resources policy and management. This paper is to adopt a win-win policy for upstream-downstream local governments that have been in water rights-related disputer or conflicts in the process of allocating water and maintaining water quality. The Win-Win Policy can be an integrated river-basin approach. We define the win-win policy, introduce the win-win case of Delaware River and Colorado River in the United States, and suggest the win-win policy for Nakdong River in South Korea. Nakdong River is chosen for this paper because it has more serious problems in preserving water quantity and maintaining water quality.

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A Study on the Safety Assessment and Damage Pattern of Water Purifier Compressors (정수기용 압축기의 안전성 평가 및 소손 패턴 분석에 관한 연구)

  • Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.28 no.2
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    • pp.21-25
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    • 2013
  • The purpose of this study is to provide basic data for the safety assessment of a water purifier when water leaks due to inappropriate maintenance and the examination of the cause of accidents related to the leak. Due to its inspection and management by non-specialists, if a leak occurs in a water purifier with the water level controller being inclined, it may result in the failure of the compressor, power supply line, PCB, etc. The analysis of the thermal diffusion pattern of water purifier compressors using a thermal image camera shows that its maximum temperature was approximately $80^{\circ}C$. In addition, its operating current was a maximum of 13 A and the system's operating current was approximately 1.7 A after the compressor was charged. It was found that the housing type power cable cover of the compressor had the effect of preventing electric shock but has poor flame resistance. Furthermore, the performance of the overload protector, PTC relays, etc., was excellent but they have potential for problems as metallic terminals were exposed, resulting in the potential of a safety related accident. The terminals and their surface damaged by the tracking showed a trace of carbonization and the resistance between terminals was measured to be approximately $8{\Omega}$. In addition, while the tracking was proceeding, the fuse and circuit breaker installed for system protection did not operate.

A Development of the Trapped Water Drainage System to Prevent the Deterioration of Deck Slab and Pavement (교면포장 및 바닥판 손상방지를 위한 내부침투수 처리시스템 개발)

  • Lee, Sang-Dal;Lee, Sang-Soon;Shin, Jae-In;Seo, Sang-Gul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.233-239
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    • 2002
  • Reinforced concrete deck slabs are directly affected by traffic loads and they are also susceptible to weather-related problems, such as cracking, reinforcement corrosion, spatting, scaling, delamination, leakage, efflorescence and so on. Some of these defects are caused by water which seeps through pavements and trapped between pavements and deck slabs. For durability of reinforced concrete deck slabs and pavements, it is very important to protect deck slabs and drain the trapped water out. To develop the trapped water drainage system, the following studies have been performed in Korea Highway Cooperation: related researches a re reviewed; for six bridges, deck slabs are thoroughly investigated; new system to effectively drain the trapped water out is proposed; the proposed system is installed and evaluated. The proposed system is proved to be effective to drain the trapped water out and is expected to increase the durability of reinforced concrete deck slabs.

Operational Improvement of Small Urban Storm Water Pumping Station (1) - Simulation of Flood Hydrograph using GIS-based Hydrologic Model (도시 소유역 배수펌프장 운영개선 방안 연구 (1) - GIS 기반 수문모형에 의한 홍수유출수문곡선의 재현)

  • Gil, Kyung-Ik;Han, Jong-Ok;Kim, Goo-Hyun
    • Journal of Korean Society on Water Environment
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    • v.21 no.6
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    • pp.682-686
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    • 2005
  • Recently some urban areas have been flooded due to heavy storm rainfalls. Though major causes of these floodings may be attributed to localized heavy rainfalls, other factors are related to urban flooding including deficiency of storm sewer network capacity, change of surface runoff due to covered open channels, and operational problems of storm drainage pump stations. In this study, hydrologic and hydraulic analysis of Sutak basin in Guri city were carried out to evaluate flooding problems occurred during the heavy storm in July, 2001. ArcView, a world most widely used GIS tool, was used to extract required data for the hydrologic analysis including basin characteristics data, concentration times, channel routing data, land use data, soil distribution data and SCS runoff curve number generation from digital maps. HEC-HMS, a GIS-based runoff simulation model, was successfully used to simulate the flood inflow hydrograph to Sutak pumping station.