• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.87-93
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• 2019

Microcapsules were prepared by using a mixture of linseed oil and a small amount of fluorescent fluid as a core material. Self-healing protective coatings were prepared by applying coating formulations containing varying amounts of microcapsules on mortar surface. After scratch or crack was generated in the coating, when the damaged region was exposed to ultraviolet light (${\lambda}=365nm$), it was observed that fluorescence emission area increased with increasing microcapsule loading. In the cases of the self-healing coatings having 20wt% or more microcapsule loading, the damaged region was almost filled with the healing agent. In water sorptivity test, the self-healing coating having 20wt% or more microcapsule loading showed a healing efficiency of about 85%. The fluorescence emission from the damaged region was easily observed at a distance of 3 m. The self-healing protective coating is expected to be useful to confirm its self-healing function with the eye.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.657-666
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• 2022

This study was conducted to verify the effect of integrated therapy program on the self-esteem, self-expression, and sexual self-determination of sexually abused women with intellectual disabilities. The subjects of this study were 8 victims who were referred to the Sexual Violence Relief Center for women with intellectual disabilities in K-area. The effectiveness of the program was evaluated to statistical significance though the pre- and post-test using the SPSS Win 25.0 program. The integrated therapy program significantly improved the self-esteem of victims(t=-4.183, p<0.001). Self-expression was significantly improved(t=-5.103, p<0.001). It was also observed that the change in behavior was positively reinforced in the sexual self-determination(t=-26.346, p<0.001). The results of this study suggest that integrated therapy program should be actively used for psychological and emotional healing of sexual assault victims with intellectual disabilities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.485-500
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• 2020

Due to various advantages such as small facilities, ease of construction and so on, the grouting technology which is widely used in construction field has developed remarkably compared with the past. However, the efforts to improve the homogeneity of quality, long-term durability and environmental problems have been continued. In recent years, new grouting method has been developed in order to solve problems such as low strength, durability and leaching phenomenon of liquid glass (sodium silicate) grouting material in Korea. A newly developed method integrates the injection material with the ground by the self-healing material of crystallization growth type. For this reason, it is known that improvement of the durability and water quality of the ground, prevention of leaching, and environment friendliness can be expected. The present study applied a newly developed method to test sites and verified its effect such as injection range, improvement effect, waterproofing performance and so on. Standard penetration test, field permeability test, borehole shear test, pressuremeter test and pH test were conducted, and the results were compared between before and after developed method application. As results of tests, the field applicability and improvement effect of developed method were proved to be excellent.

• Clean Technology
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• v.17 no.2
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• pp.85-96
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• 2011

Self-healing materials are a class of smart materials that have the structurally incorporated ability to repair damage caused by mechanical usage over time. A material (polymers, ceramics, metals, etc.) that can intrinsically correct damage caused by normal usage could lower production costs of a number of different industrial processes through longer part lifetime, reduction of inefficiency over time caused by degradation, as well as prevent costs incurred by material failure. The recent announcement from Nissan on the commercial release of scratch healing paints for use on car bodies has gained public interest on such a wonderful property of materials. This article is a second part of healing materials dealing with inorganic engineering materials such as metals, ceramics, and concrete. The healing mechanisms developed for the inorganic materials are to be discussed with the future prospect.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.92-100
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• 2022

In this paper, to evaluate the effect of SC on the crack self-healing performance and mechanical recovery performance of cement composites, encapsulated intumescent inorganic material-based solid healing materials were prepared. SC was mixed with cement composite materials to evaluate the basic properties, permeability test, and load reload test. SC slightly improved the flow of cement composites, and the compressive strength decreased by about 10 %. Also, the flexural strength decreased by about 30 %. It was found that when SC was mixed with the cement composite material by 5 %, the crack self-healing rate of Plain was improved by about 𝜟10 %. As a result of the load reload test, it was found that the mechanical recovery rate of Plain was improved by about 𝜟20 %. In addition, as a result of analyzing the correlation between the crack self-healing rate and the mechanical recovery rate by the load reload test, it is judged that the healing area of the Plain can be increased due to SC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.221-222
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• 2021

Bacterial self-healing concrete is known to improve the durability of concrete by preventing the propagation of microcracks. In the literature, bacteria prevent the corrosion of rebar by inhibiting water transfer through crack, but also can promote the corrosion by acting as an ion acceptor in the rust generation mechanism. Therefore in this study, the electrochemical analysis of bio-filmed rebar was conducted to explore the effects of the self-healing bacteria on the bare rebar without cement composite. As a result of the experiment contradicting trends for Ecorr and Icorr occurred and additional experiment will be conducted in various environments to collect data on the mechanism of corrosion of rebar by bacteria.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.149-150
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• 2023

Although concrete is a material widely used in the construction industry, it is very vulnerable to cracking and has a disadvantage in that durability deteriorates when cracks occur. When cracks occur, harmful factors are introduced through the micro-cracks of the structure, reducing durability. Therefore, in this study, as part of a study to alleviate the problems of maintenance and durability deterioration due to cracks in concrete structures, the mechanical properties of self-healing mortar according to the size of the capsule made of cement material were reviewed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.81-87
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• 2020

Crack control is essential to increase the durability of concrete significantly. Healing of crack can be controlled by rehydration of unreacted clinkers at the crack surface. In this paper, by comparing the results of isothermal calorimetry test and regression analysis, the Parrot & Killoh's cement hydration model was verified and clink er hydration model was proposed. The composition and quantification of hydration products were simulated by combining kinematic hydration model and thermodynamic model. Hydration simulation was conducted using the verified and proposed hydration model, and the simulation was performed by the substitution rate of clink er. The type and quantity of the final hydration product and healing product were predicted and, in addition, the optimal cementitious material of self-healing concrete was selected using the proposed hydration model.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.593-599
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• 2022

In this study, a crack monitoring system capable of detecting cracks based on image processing techniques was developed to effectively check cracks, which are the main damage of concrete structures, and a program capable of imaging and analyzing cracks was developed using machine vision. This system provides objective and quantitative data by replacing the appearance inspection that checks cracks with the naked eye. The verification of the development system was applied to the construction site of a self-healing concrete water tank to monitor the crack and the amount of change in the crack width according to age. In the case of crack width detected by image analysis, the difference from the measured value using a digital microscope was up to 0.036 mm, and the crack healing effect of self-healing concrete could be confirmed through the reduction of crack width.

• Polymer(Korea)
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• v.39 no.1
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• pp.56-63
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• 2015

The object of this study is to prepare microcapsules containing a diisocyanate compound, apply them to self-healing protective coating, and evaluate the self-healing capability of the coating by atmospheric moisture. Isophorone diisocyanate (IPDI) polymerized under humid atmosphere, indicating that IPDI can be used as a healing agent. Microencapsulations of IPDI were conducted via interfacial polymerization of a polyurethane prepolymer with diol compounds. The formation of microcapsules was confirmed by Fourier-transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The mean diameter, size distribution, morphology and shell wall thickness of microcapsules were investigated by optical microscopy and scanning electron microscopy (SEM). The properties of microcapsules were studied by varying agitation rates and diol structure. The self-healing coatings were prepared on test pieces of CRC board. When scratch was generated in the coatings, the core material flew out of the microcapsules and filled the scratch. The self-healing coatings were damaged and healed under atmosphere with 68~89% relative humidity for 48 h, and SEM and impermeability test for the specimens showed that the scratch could be healed by atmospheric moisture.