• Journal of the Korean Society of Clothing and Textiles
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• v.4 no.1_2
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• pp.43-48
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• 1980

The effect of free fatty acid in fatty soil on the detergency of particulate soil was investigated. Cotton lawn fabric was soiled with the mixture of polmitic acid, hydrogenated fat, paraffin oil and iron oxide black altering the contents of palmitic acid and was laundered with different sur-fastants under various temperature and alkalinity. The rate of soil removal was estimated by means of the spectoometic analysis of iron on the fabric before and after washing. The results of dergency were compared those obtained by reflactance and K/S value from Kubelka-Munk equation which were derived from reflactance measurements.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.345-350
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• 2001

Reinforced concrete is, in general, known as a high durability material due to a strong alkalinity of cement. Probable concrete cracks could incur steel corrosion of RC structures and then could easily deteriorate the concrete durability, which can be fully secured by a systematic quality control for the construction of concrete structures. For the corrosion protection of reinforcing steels in concrete, however, current design specifications of concrete cover depth do not in-depth consider the effect of the cracks as well as the chloride content of RC structures. Therefore, appropriate provisions for concrete cover depth should be coded by considering the influence of concrete cracks on the corrosion of reinforcing steels. The objective of this research is to investigate pertinent cover depth, which can prohibit rebar corrosion, on the basis of experimental corrosion measurements of reinforcing steels on crack characteristics such as the width, depth and frequency of concrete cracks.

• Corrosion Science and Technology
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• v.8 no.6
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• pp.232-237
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• 2009

Copper tubes are widely used in the distribution systems of drinking water throughout the world because of their excellent corrosion resistance, high thermal conductivity, and ease of fabrication. However, corrosion problems from copper tubes as blue water phenomenon and leakage have been reported appreciably. The effect of pH on the corrosion behavior of copper tube for tap water was investigated by electrochemical voltammetric techniques in synthetic tap water. And the copper corrosion cases were discussed from the viewpoint of factors affecting the corrosion rate such as pH, alkalinity, LSI(Langelier Saturation Index), and concentration of bicarbonate and dissolved carbon dioxide.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.73-84
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• 1996

Fluoride was first introduced into the drinking water of residents of Grand Rapids, Michigan in 1945 for the prevention of dental caries. Ever since, growing numbers of communities favor fluoridation. Now, over 7000 communities in the United States are adding F(0.7~1.2ppm) to their drinking water. The most effective to prevent tooth decay is putting lower concentrated fluoride(F, 0.7~1.2ppm) into drinking water. However, exact fluoride injection amount have not been decided, because the research of the fluoride injection effect was insufficient. Therefore, after separating fluoridation and non-fluoridation into public water supplies, we investigated concentration of fluoride, alkalinity, Al, Ca, Mg, evaporation residuals in APT, domestic, commercial area. Then, we decided allowable concentration of fluoride, injection point of fluoride in water supply system, cost effectiveness.

• Textile Coloration and Finishing
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• v.11 no.3
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• pp.23-31
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• 1999

In order to investigate the detergency of the mixture of compact detergent and bleaching agent to fabric stained with a coffee and a red wine, respectively, and a japanese wet stained fabrics, to evaluation of detergency was studied under various washing conditions. In order to study the effect of alkaline agent addition on the detergency, the soda ash was added in the compact detergent system. The results are as follows : In a low temperature washing condition, the alkalinity of washing liquor effected more the removal of the composite stained fabrics than that of oilic stained fabrics. For the colored stained fabric such as red wine stained sample, the influence of the repeated washing treatment on the detergency was not significant factor. On the other hand, the influence of the repeated washing treatment for the coffee stained and japanese wet stained fabric on the detergency was gradually increased.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.101-107
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• 1997

Recently, as the raw water quality becomes to be polluted and the seasonal and local variation of water quality becomes to be severe, an exact control of coagulant dosing have been required in the water treat- ment plant. The amounts of coagulant is related to the raw water quality such as turbidity, alkalinity, water temperature, pH and edectrical conductivity. However the process of chemical reaction has not been clarified so far, so the dosing rate has been decided by jar-test, which is taken one or two hours. For the sake of this coagulant dosing control, fuzzy neural network to fuse fuzzy logic and neural network was proposed, and the scheme was applied to automatic determination of coagulant dosing rate. This controller can automatically identify the if-then rules and tune the membership functions by utilizing expert's cintrol data. It is shown that determination of coagulant dosing rate according to real time sensing of water quality is very effect.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.241-247
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• 1997

Reinforced concrete is in general known as high durability construction material under normal enviroments due to strong alkalinity of cement. Marine and harbour concrete as well as concrete mixed with seasand for fine aggregate are exposed to detrimental saltwater wich cause to accel-eate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken due to carbonation and crack in cover concrete, concrete durability rapidly decrease by corrosion of reinforcement steel embedded in concrete. This research is to investigate basic physical properties of various corrosion inhibitors and to evaluate their corrosion resistance in concrete mixed with seasand. The object of this study is develop appropriate corrosion protection systems so as to enhance the durability of concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.693-696
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• 1999

Reinforced concrete is, in general, known as high durability construction material under normal environments due to strong alkalinity of cement. It is , however, well known that moderate or minor cracks in reinforced concrete should be most serious causes to deteriorate the durability of RC structures. Furthermore, chloride contents penetrating through unexpected cracks in reinforced concrete bridges get to weaken corrosion resistance of reinforcement steel in concrete and than to accelerate the deterioration of concrete durability. The objective of this experimental research is 1) to evaluate the effect of various corrosion protection system for reinforced concrete specimens with moderate or minor cracks which are exposed to cyclic wet and dry seawater, and then 2) to develop effective corrosion protection system for reinforced concrete bridges under the exposure of various detrimental environments such as seawater, deicing and etc.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.718-723
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• 2000

Reinforced concrete is in general, known as high durability construction material under normal environments due to strong alkalinity of cement. It is, however, well known that moderate or minor cracks in reinforced concrete should be most serious causes to deteriorate the durability of RC structures. Futhermore, chloride contents penetrating through unexpected cracks in reinforced concrete bridges get to weaken corrosion resistance of reinforcement steel in concrete and then to accelerate the deterioration of concrete durability. The objective of this experimental research is 1) to evaluate the effect of various corrosion protection systems for reinforced concrete specimens with moderate or minor cracks which are exposed to cyclic wet and dry seawater, and then 2) to develop effective corrosion protection systems for reinforced concrete bridges under the exposure of various detrimental environments such as seawater, deicing and etc.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.37-38
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• 2013

The fine powder obtained from the manufacturing process of recycled coarse aggregate contains unhydareted cement particles on their surface. It is believed that the alkalinity of the powder (11.0-12.5) is enough to active the slag-based composites. In this paper, the obtained powder was sieved and divided into two sizes, i.e., 0.08 mm and 0.3 mm, and added to the slag-based mortar. Results showed that the fine powder had an effect on the slump and the compressive strength of slag-based composites. With the different pH values of the powder, it could be seen that the distance between the two level powders. And found the peak 28 days compressive strength as the replacement ratio of the recycled aggregate powder changed. The findings from this study provide an indication that with achieved compressive strength, the fine powder can be used in a light weight concrete.