• Transactions of Materials Processing
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• v.11 no.4
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• pp.295-301
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• 2002

Recently, design concepts of vehicle will have to consider the safty and economy of fuel consumtion. The hydroforming technology has applied to increase strength, and to decrease weight, cost and part count. The hydroforming has been recognized as general technique in automotive industry. This paper deals with the trends of automotive application of hydroforming, new hydroforming technologies, facilities.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.379-382
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• 2000

In this paper, we evaluated the suitability of converter slag as concrete aggregate by measuring physical and chemical characteristics of converter slag. The converter slag mainly contains SiO₂and CaO as the chemical composition. The reaction with water and a little of free CaO in the slag causes slag's volume to expanse. Therefore, we used several aging method in order to decrease the characteristics of slag volume expansion. Then the compressive strength of concrete with the converter slag aggregate is measured.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.335-338
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• 2003

Flexural test and parametric study by FEM analysis on 6.0m long reinforced concrete beams strengthened by GFRP are reported in these tests. The selected variables are strengthened plate length, plate thickness. The effects of these variables are discussed. The results generally indicate that the flexural strength of strengthened beams is increased. The results of FEM analysis show that the more strengthening GFRP is the more stress of GFRP is decrease when failure mode is peeling failure.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.261-266
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• 1998

The purpose of this study is to present the reference data on the development of undispersed underwater mortar for augered pile under various replacement ratio of fly-ash. According to the experimental results, when 10% of fly-ash is mixed under mix proportion of 1:1.5(c:s), as strength and shrinkage decrease slightly, whereas fluidity increase, high quality mortar for augered pile can be achieve in case above condition is applied.

• Textile Coloration and Finishing
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• v.7 no.1
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• pp.23-31
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• 1995

Changes of the properties of waterproof and moisture-permeable nylon fabric were investigated when softener, anti-static agents, anti-biosis agents were added to the polyurethane resin solution, and when they were applied after resin coating. The adding method of finishing agents into polyurethane layer resulted in an increase in water permeability but a severe decrease in peeling strength. It was found that the desired functionality such as softness, anti-staticity, anti-biosis were successfully introduced into waterproof and moisture-permeable nylon fabric by after-treatment of finishing agents.

• Transactions of Materials Processing
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• v.9 no.6
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• pp.561-566
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• 2000

Recently, the hydroforming technology has been recognized as a general technique in manufacturing industry, especially in automotive industry. Hydroforming is applied to increase strength, and to decrease weight, cost and parts. Hydroforming is based on the inflation of, for Instance, a tube, coupled with axial or radial compression and by subsequent expansion and sizing against the die wall. Expansion, axial feeding, calibration are important parameters in this process. In this paper, the effects of various parameters such as internal pressure, axial feeding and friction on hydroforming of automotive bumper rail have been considered.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.911-914
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• 2000

Surface glossing and physical properties of exposed concrete varied with blast furnace slag content are dsicussed in this paper. According to experimental results, as the content of blast furnace slag increases, concrete gains high strength moderately at later stage and surface glossing increase. It shows that glossing decrease with age. Surface glossing shows high as W/B decreases and surface coating is applied. Concrete according to form type shows good results in surface glossing in order for acryl form, fancy form and steel form.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2011-2013
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• 2000

Insulators of transmission line have been frequently damaged by lightning flashover. Arcing horns have been installed on string sets to protect insulators from the flashover. But reclosing number can be increased by the decrease of insulation strength and they are worrying it. Then this paper analyzes the installation effects of the arcing horn.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.627-630
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• 2004

This paper investigates a study on the bending behavior of beam strengthened with CFS under repeated loading. The test specimen consisted of 20cm in width, 40cm in depth, and 15cm in CFS width. We find the strength decrease under repeated loading test comparing with the monotonic incremental loading test.

• Environmental Engineering Research
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• v.10 no.1
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• pp.22-30
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• 2005

Nitrite accumulation is not unusual in batch processes such as sequencing batch reactor (SBR) with high-strength of ammonium or nitrate wastewaters. A possible mechanism of nitrite inhibition on Acinetobacter was depicted in a biochemical model, which the protonated species, nitrous acid form of nitrite, affects proton relating transport at the proton-pumping site crossing the cell membrane under unlimited carbon and phosphorus conditions. This effect exerts inhibition of phosphorylation under aerobic condition and yields low APT/ADP ratio, consequently decrease poly-P synthesis and phosphorus uptake from outside the cell in the model.