• Composites Research
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• v.28 no.6
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• pp.395-401
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• 2015

This study investigated the thermal stability of Grubbs' catalyst and its reactivity with self-healing agents for self-healing damage repair. Four types of Grubbs' catalyst supplied by manufacturers were considered and each catalyst was tested in as-received and grinded conditions. Four types of self-healing agents were prepared by varying the mixing ratio of dicyclopentadiene (DCPD) and 5-ethylidene-2-norbonene (ENB). Heat flows as a function of temperature were measured through a differential scanning calorimetry (DSC) to determine the thermal stability of catalysts. Reaction heats of self-healing agents with the catalyst were measured to evaluate the reactivity of the catalyst. For this evaluation, Fluka Chemika Grubbs' catalyst was used based on the maximum temperature and the time to reach the maximum temperature. According to the results, catalysts had different shapes depending on the manufacturer and the results showed that the smaller the size of the catalyst the higher the reactivity with self-healing agents. As the ENB ratio in self-healing agents increased, the maximum temperature increased, and the time to reach the maximum temperature decreased. As the amount of the catalyst increased, the maximum temperature increased, and the time to reach the maximum temperature decreased. Considering the thermal stability of the catalyst and its reactivity with the self-healing agent, combination of 0.5 wt% catalyst and the D3E1 self-healing agent was optimal for self-healing damage repair. Finally, as the thermal decomposition may occur depending on the environmental temperature, the catalyst must not be exposed to temperature higher than that is necessary to maintain the thermal stability of the catalyst.

• Composites Research
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• v.15 no.2
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• pp.32-39
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• 2002

This study focused on the introduction of processing procedure for microcapsules loaded with the healing agent and then microcapsules with the healing agent were manufactured by experiments. The DCPD (dicyclopentadiene) was used for the healing agent and the shell of microcapsules was consisted of urea-formaldehyde resin. The magnitude and the site distribution of microcapsules were measured by a particle size analyzer using laser diffraction technique. Thermal analysis was conducted by using a DSC fur the healing agent, microcapsules without the healing agent, and microcapsules with the healing agent. Also thermal stability was investigated by using a TGA under continuous and isothermal heating conditions far the healing agent, microcapsules without the healing agent, microcapsules with the healing agent. According to the results. microcapsules with the healing agent were verified to be so thermally stable that the healing agent could not evaporate until the shell of microcapsules were burned.

• Polymer(Korea)
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• v.37 no.3
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• pp.356-361
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• 2013

Microcapsules of two different self-healing agents, 5-ethylidene-2-norbornene (ENB) and ENB with a crosslinker, surrounded by a melamine-urea-formaldehyde shell were manufactured. In this work, a red dye was incorporated into the self-healing agents as a tracer for better visual observations. It revealed that the incorporation of a red dye into self-healing agents did not disturb the formation of microcapsules from the examination of thermal resistance, particle size/size distribution and morphology of the resulting microcapsules. Releasing of self-healing liquid into the induced crack from ruptured microcapsules and filling between crack planes were observed using an optical microscope. Also observed was the reaction of filled healing agent with embedded Grubbs' catalyst in an epoxy coating layer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3998-4004
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• 2010

This study investigated the agents for self-healing system that could be developed to prevent UST(underground storage tank) from leaking. The system involves short range wireless communication to locate a leakage. Four commercially available silicons are arbitrarily chosen to evaluate suitability as a self-healing agent through a series of laboratory experiments. finally the experiments are simulated using computational Fluid Dynamic Program.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.35-42
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• 2014

Thermal analysis properties and adhesive properties of self-healing agents were evaluated through differential scanning calorimetry, reaction heat measurement, and adhesive shear test. D1E0, D3E1, D1E1, D1E3, and D0E1, depending on the mixing ratio of DCPD and ENB, were considered as self-healing agents. The amount of Grubbs' catalyst, depending on the type of self-healing agents, was varied from 0.1 wt% to 1.5 wt%. In the case of DCPD, the polymerization reaction occurred faster and the stabilized adhesive strength increased as the amount of catalyst increased; however, a large amount of catalyst was required. ENB had excellent reactivity with a small amount of the catalyst; however, high reaction heat was observed at the early stage of polymerization. Thermal analysis properties and adhesive properties of self-healing agents can be controlled by varying a mixing ratio of DCPD and ENB. Among the self-healing agents used for this study, the D3E1 would be one of the most preferable candidates with regard to maximum adhesive strength, reaching time to maximum adhesive strength, stabilized adhesive strength, and reaction heat.

• The Monthly Diabetes
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• s.208
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• pp.18-20
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• 2007

당뇨병 치료 방법은 식사조절, 운동, 교육, 약물치료, 인슐린 주사 등이다. 운동은 당뇨 치료의 기본이다. 성인 당뇨병환자의 대부분인 제 2형 당뇨병에서 운동은 혈당을 낮추며, 체중을 감소시키고, 체내 지방질을 좋아지게 하며, 심장.혈관.신경계 및 망막 합병증을 감소시킨다. 인슐린 주사를 반드시 맞아야 하는 제 1형 당뇨병환자가 운동을 하면 인슐린 주사를 줄이거나 맞지 않을 수 있다.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.29 no.1
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• pp.13-24
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• 2020

Autotransplantation is the surgical repositioning of an autogenous erupted or unerupted tooth from one site to another in the same individual. This treatment is indicated in traumatic tooth loss, teeth with severe caries, congenitally missing teeth, teeth with bad prognosis and in case of developmental anomalies of teeth. The following 2 cases describe the potential to utilize autotransplantation to replace hopeless teeth with sound wisdom teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.108-115
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• 2017

Numerous therapeutic approaches are available for impacted teeth, including orthodontic retraction, implantation, and autogenous tooth transplantation. Autotransplantation is a promising method, especially for juvenile patients, as it enables preservation of the function of the periodontal tissues, as well as continued alveolar bone growth. This report describes autotransplantation in two cases in which the tooth was fully-ectopically impacted. With case 1, an ectopically impacted premolar was extracted and transplanted in an upright position, and regenerative endodontic treatment was performed using a platelet-rich fibrin clot and mineral trioxide aggregate (MTA). With case 2, a calcifying odontogenic cyst with an impacted left mandibular second molar was treated by enucleation. The tooth was transplanted into the proper position 3 months after enucleation, and endodontic treatment was performed using MTA. In both cases, autotransplantation appeared to provide a simple and rapid treatment option for patients with ectopically impacted teeth. These cases demonstrate that autotransplantation of ectopically impacted teeth is a viable treatment option rather than implant placement or prosthesis, especially in juvenile patients.

• Journal of the korean veterinary medical association
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• v.7 no.1
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• pp.20-27
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• 1963

• The Monthly Diabetes
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• s.136
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• pp.36-37
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• 2001

케톤산혈증은 대개 제 1형 당뇨병 환자에게서 잘 발생한다. 케톤산혈증에 빠지면 의식이 혼탁해지고 구토 및 복통을 호소하게 되며 호흡곤란과 함께 체온이 떨어지게 되는데 케톤산증은 자가치료가 불가능하기 때문에 발견 즉시 병원으로 이송하여 인슐린 주사와 같은 적절한 치료를 받아야 한다.