• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.113-121
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• 2019

In this study, self - healing microcapsules which can be mixed directly with cement composites were prepared, and the quality and crack healing performance of cement composites with self - healing microcapsules were evaluated. In the past, it has been focused on evaluating self-healing capsules and crack healing properties. Therefore, self - healing microcapsules have been studied for their effect on the quality of cement composites when mixed with cement composites. The table flow and the air flow rate of the cement composite material mixed with self-healing microcapsules were found to have no significant influence on table flow and air volume regardless of mixing ratio. Compressive strength and splitting tensile strength tended to decrease with increasing capsule mixing ratio. As a result of evaluation of crack healing properties according to water flow, initial water permeability decreased, and reaction products were generated over time and cracks were healed.

• Proceedings of the Korea Fashion and Costume Design Association Conference
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• 2004.06a
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• pp.89-92
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• 2004

비만과 질병의 관계가 밝혀짐에 따라, 비만은 세계보건기구에서 정한 치료를 요하는 질병 중의 하나로 구분되고 있다. 비만의 치료는 과체중이 바람직한 체중으로 감소되고, 감소된 체중이 적어도 5년 동안 유지되는 것으로 정의하여, 이를 기준으로 보았을 때 비만에 대한 치료율은 암의 치유율 보다 낮아서, 비만의 완치가 얼마나 어려운지를 잘 말해주고 있다.(중략)

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.389-396
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• 2021

In this paper, it was evaluated that the effect of self-healing microcapsules on the quality and healing properties of cement composites. In the mixing of microcapsules, the plastic viscosity and yield stress of the cement composites decreased due to the particle properties of the microcapsules, and decreased in proportion to the mixing ratio. The table flow showed a tendency to decrease as the core material acted as a stimulant due to the loss of microcapsules, and the compressive strength could be supplemented through unit quantity correction. As a result of evaluating the effect of microcapsule mixing on the healing properties of cement composites, it was found that the unit water flow rate decreased by the healing reaction immediately after crack initiation. When more than 3% of microcapsules were mixed, it was found that there was a healing rate of more than 95% at 7 days of healing age.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.59-66
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• 2020

In this study, self - healing solid capsules of crystal growth type which can be mixed directly with repair mortar were prepared, and the quality and crack healing performance of repair mortar with self - healing solid capsules were evaluated. The table flow and the air flow rate of the repair mortar material mixed with self-healing solid capsules were found to have no significant influence on table flow and air volume regardless of mixing ratio. Compressive strength tended to decrease with increasing capsule mixing ratio. As a result of evaluation of crack healing properties according to constant water head permeability test, initial water permeability decreased, and reaction products were generated over time and cracks were healed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.568-575
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• 2023

This paper aims to evaluate the quality characteristics and healing performance of precast concrete incorporating self-healing technology as a key technique for the construction of smart cities. The study found that precast concrete mixed with hybrid capsules exhibited a tendency of reduced slump and air content, impacting the quality characteristics. Specifically, the slump decreased by up to 14 %, and the air content by up to 9 %. Moreover, the inclusion of hybrid capsules in the concrete resulted in a maximum decrease of 16 % in compressive strength and 18 % in flexural strength. However, the introduction of hybrid capsules significantly enhanced the crack healing performance. The assessment through water permeability tests showed that the healing rate of 0.3 mm crack width after a 28-day healing period improved as the mixing ratio increased, with the healing rates at 1 %, 3 %, and 5 % hybrid capsule mixtures observed to increase by approximately 16 %, 25 %, and 32 %, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.383-388
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• 2021

In this study, constant head water permeability test was adopted to evaluate self-healing performance of mortars containing inorganic healing materials which consist of blast furnace slag, sodium sulfate and anhydrite. Clinker powder and sand replaced for a part of cement and fine aggregates. On constant head water permeability test for self-healing mortars, unit water flow rate of mortar specimens were measured according to crack width and healing period. As a result of evaluating the healing performance of self-healing mortar, it was confirmed that with the initial crack width of 0.3mm, the healing rate at healing period of 28 days increased by more than 30%p compared to plain mortar, greatly improving the healing performance. Furthermore, the coefficient(α) which was estimated from the relationship between crack width and unit water flow rate was used for calculating equivalent crack width. By analyzing the correlation of healing rate and equivalent crack width, the time and initial crack width attaining healing target crack width were predicted.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.134-142
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• 2020

In this study, in order to evaluate the self-healing performance of cement composites the self-healing test method and the analysis method were suggested by applying constant water head permeability test, chloride migration test and repeated bending test. The method of making a cracked specimen and controlling crack width are also proposed. Constant head water permeability test can evaluate the healing performance by using the decreasing rate of water flow passing through the crack zone of a specimen. Furthermore, the equivalent crack width can be used to intuitively investigate the healing effect with healing period. The chloride migration test can evaluate the healing rate by the decreasing rate of the diffusion coefficient obtained by ASTM C 1202. Mechanical healing performance can be evaluated using ISR and IDR estimated from load vs. CMOD relationship graph obtained through the repeated bending test. Finally, the applicability of proposed self-healing evaluation methods was examined by testing mortar specimens with or without self-healing agents.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.181-186
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• 1992

A retrospective analysis was undertaken for 22 patients with early glottic cancer ($T_1N_0M_0$; 17, $T_2N_0M_0$; 5) who completed curative radiotherapy at the Department of Therapeutic Radiology, Chonnam University Hospital between November 1985 and December 1990. Median follow-up period was 39 months. The 3 year actuarial survival rate of T1, T2 was $81\%$ and $80\%$. respectively. Three patients ($13\%$) showed second malignant tumors and the site of the new primary was esophagus in two patients and lung in the other one. They were excluded from the local control analysis. The local control rate of T1. T2 group was $66\%$ and $50\%$. respectively. The surgical salvage rate and the ultimate local control rate of T1 group was $80\%$ (4/5) and $93\%$. and that of T2 group was $100\%\;(2/2)\;and\;75\%$. respectively. The local control rates of T1 stage were evaluated according to the various parameters. The local control rate of the superficial and exophytic lesion was better than that of the ulcerative and infiltrative one, and the involvement of anterior commissure was not seemed to be adverse prognostic factor. But the protracted treatment time showed the adverse effect on the local control of the disease. All of the eleven patients controlled by primary radiation therapy have maintained their voice well without any significant complication.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.294-301
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• 2003

This study was performed to compare the effects of hydrocolloid(Duoderm$\circledR$, HC in this study) and hydrogel (Nu-Gel$\circledR$, HG in this study) occlusive dressing materials on degree of exudate, wound contraction, epithelialization, and healing of full-thickness skin wound in dogs. Three wounds measuring 2${\times}$2 cm in size were created bilaterally(6 wounds/dog) on the dorsolateral aspect of the trunk of 12 dogs. In each dog, the wounds were treated with HC, HG, and normal saline, respectively. For a 4 week period, the wounds were evaluated gross aspects and histopathological aspects. There were no statistically significant differences between treatment groups in percentage of wound contraction, percentage of epithelialization, and percentage of wound total healing during the first week. Significant differences were first detected on day 14. On day l4(P < 0.01) and 21 (P < 0.05), mean percentage of epithelialization of HG-treated wound was significantly greater than those in HC- and normal saline-treated wound. Mean percentage of wound contraction of HG-treated wound was significantly greater than that in HC- and control wounds on day 21(P< 0.05). On day 21, mean percentage of wound healing of HG-treated wound was significantly greater than that in HC- and control wounds(P < 0.02). On day 1, 4, and 7 after wound creation, although severe infiltration of PMN (polymorphonuclear leukocyte) cells in HC- and control wounds were observed in the subcutis and moderate infiltration of PMN cells in HG-treated wound were observed in the subcutis, we did not detect significant differences. On day 14 after wounding creation, in the wounds treated with HG dressing, epithelial cells were found over the surface, and edema further decreased in the tissue under the wounds, and the granulation tissue was replaced with collagen fibers. On day 21 after wound creation, in HG-treated wound compared with other experimental material-treated wounds, regenerated epidermis covered most of the wound surface, and the granulation tissue was more replaced with collagen fibers than that on day 14. Overall results indicated that the use of hydrogel dressing materials(Nu-Gel$\circledR$) as hydrocolloid dressing (Duoderm$\circledR$) materials and normal saline treatment on full-thickness skin wounds in dogs increased the rate of healing at repair stage.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.584-592
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• 2022

In this paper, a study was conducted to improve self-healing and strength properties using sodium acetate. The developed inorganic-organic self-healing materials and recycled sodium acetate were manufactured to evaluate self-healing and permeability reduction properties. As a result of the experiment with recycled sodium acetate, the compressive strength of the material prepared with anhydrous and trihydrate at a ratio of 7:4 was higher than that of the mixture using anhydrous. It was confirmed that the compressive strength was improved by 3~7 %. In addition, the maximum permeability reduction rate was 92.6 %, which satisfied the self-healing properties.