• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.358-360
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• 2000

Measurement and analysis for earth resistivity and grounding resistance of Jeon-Ju's widearea-waterworks water pipe line. This result propose to improvement method for exactness analyze the causes for lack of corrosion voltage.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.554-558
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• 2000

Bacteria were isolated and identified from an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16-megabyte DRAM semiconductor manufacturing. Scanning electron microscopic and microbiological observations revealed that the primary source of the bacteria isolated from the UHPW was detached cells from biofilms developed on the pipe wall through which the UHPW, a man-made and extremely nutrient poor environment, was passing. About 63-65% of the bacteria isolated from the UHPW and the pipe wall were Gram-positive, whereas only 10% of the bacteria isolated from the feed water were Gram-positive. The of Gram-positive bacteria and seven genera of Gram-negative bacteria. Strains of the UHPW bacteria effectively adhered to and formed a biofilm on the surface of polyvinyl chloride (PVC) pipe.

• Journal of the Mineralogical Society of Korea
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• v.19 no.2 s.48
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• pp.111-121
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• 2006

SEM, stereo-microscope, XRD, scale-removal experiment were used for the study of mineralogical characteristics and possibilities of removal and depress of scales in water pipe. Scales are mostly composed mainly of iron minerals with minor Si and Ca containing minerals. This experimental study showed that the combination of Mg and brass was most effective on removing scales.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.41-46
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• 2002

Recently, the design and construction of massive concrete structures are increased, But, the temperature rise within a large concrete mass makes the construction of massive concrete structures be very difficult. Therefore, various techniques of the thermal stress control of the mass concrete have been widely used. One of them is pipe-cooling which reduces the temperature of concrete with flowing water. It was shown to be possible to construct the massive concrete foundation of urban bridge successfully by application of pipe-cooling system with steel pipe and water circulation. It was also found to expected to make it possible to reduce the probability of thermal crack development in a massive concrete foundation of urban bridge by pipe-cooling system.

• Proceedings of the Korean Sanitation Conference
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• 2001.11a
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• pp.119-140
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• 2001

This experiment from March 1, 1998 to August 31, 2001 through XRD, XRF, SEM, EDS had effects as follows. 1. According to the results of test using XRD and EDS, we found that the main ingredients causing corrosion of steel pipe was ${Fe_2}{O_3}$, that of cast iron pipe was $CaCO_3$. 2. The main ingredient of corrosion products in a water pipe was Fe. On an average Fe occuied 93.36% of corrosion products in case of steel pipe while it did 85.47% in case of cast iron pipe. 3. In case of a piped water passed through SCALE BUSTER over 10 times, the corrosion products decreased largely by the galvanic effect and sacrifical anode caused by the concerntration of Zn.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.343-354
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• 2012

A electro-foaming fusion wrap fitting for polyethylene sewer pipe was built and foaming mechanism has been studied. A foaming sheet, supporting sheet and clamping band is assembled into a all-in-one structured electro-foaming fusion wrap fitting. To specify foaming and fusion of electro-foaming fusion wrap for PE sewer pipe, series of fusion tests were performed in various conditions. A parallel plate compression test up to 50 % of inner diameter deflection has been performed to check integrity of fusion quality and it was found that there were no visible signs of crack in wrapped area of fitting. Also air tightness test based on KS M 3511-2 has been performed to evaluate perfectness of wrap fusion quality and we found there were no pressure drop up to 10 times higher value than KS standard regulation.

• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.215-225
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• 2000

The structural integrity of the fuel test loop (FTL) in a Korean experimental reactor is evaluated when the FTL, submerged in a water environment, is subjected to a postulated pipe rupture. The analyses are performed under static and dynamic conditions, imposing the thrust force history at each postulated pipe rupture section. Through analysis the following results are found: l) A double ended guillotine can not be expected based on the toughness of the material, 2) the structural integrity of the chimney surrounding the FTL would not impede the structural integrity by the pipe whip. All analyses are performed by finite element methods.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.7-12
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• 2003

heat pipe with screen meshed wick. The heat pipe was designed in 200 screen meshs, 500 mm length and 12mm O.D tube of copper, water as working fluid and nitrogen as non-condensible gas. Heat pipe used in this study has evaporator, condenser and adiabatic section, respectively. Experimental data of wall temperature distribution along axial length is presented for heat transport capacity, condensor cooling water temperature change, degrees of an inclination angle, and operating temperature.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.267-270
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• 1998

Current valve protection cover had problem that the hight of cover cap and road level could not match when the road was repaired and overcovered. But new developed device can solve this problem by forming several grooves in the connecting pipe. This device is devided into col=netting pipe (down side) and cap part.(upper side) On the outside diameter of connecting pipe, several horizontal grooves and two vertical grooves are formed. Through the horizontal grooves, the hight of cap part ran be adjusted with ground level. Therefore, this device can help easy maintenence in running water pipe.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.133-140
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• 2016

Most small weir installed in Korea is concrete solidated weir. Fixed weir causes stagnant flow, which leads to deposit sediment just upstream of weir. As time goes on, it would induce reduction of water storage capacity and invoke the serious water quality issues. Therefore, there has been a growing interest in movable weir. Especially, the flexible rubber weir is easy to install and possible to operate in extreme environments. However, even though this type can be flatable, it is also not free from sediment deposition problem. Thus, to enhance the ability of releasing deposition the bypass pipe was constructed underneath it. In this study the performance of its ability was examined with hydraulic model test. This bypass pipe was designed with 3 different dimensions to connect between each bottom of upstream and downstream of a weir, such as Type A, B, and C. The efficiency of drainage of deposition upstream was studied under two water of upstream and sediment heights. In addition, the ability of sediment emission through the bypass pipe after the pipe was blocked by debris like soil, vegetation et al. was examined by video monitoring. From this study, it was suggested a dimensionless equation which show the relationship of variable parameters and amount of emission sediment through bypass pipe. And it was found that the most significant factors on efficiency of releasing were elbow angle and discharge, and the ability of emission when the pipe was blocked was most highly influenced in tilting length.