• Journal of Welding and Joining
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• v.17 no.1
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• pp.82-87
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• 1999

The basic remote sleeve repair-welding technology by the pulsed Nd:YAG laser for increasing the lifetime of the steam generator tube in a nuclear power plant has been developed. The relationship between the connection width and welding parameters have been investigated for the fundamental research to apply the sleeve-repair-welding technique to the nuclear industry. The Inconel 600 tube and Inconel 690 sleeve used for high temperature and high pressure service were welded as round lap welding by Nd:YAG laser. It was observed that the tensile shear strength, 340MPa of the welded specimen is equivalent to about 60% of that of the base metal (Inconel 600), 550MPa. The difference between the hardness of the base metal and that of the laser welds was about 10%. Ductile fracture was partly occurred in the weld but the cracking has not been observed. In spite of absence of the crack, the strength of welds was not sufficient in terms of the tensile shear strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.141-144
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• 2006

The main purpose of this study is to develop a Sprayed FRP repair and strengthening method, which is a new technique for strengthening the existing concrete structures by mixing carbon or glass shot fibers and the epoxy or vinyl ester resins with high-speed compressed air in open air and randomly spraying the mixture onto the concrete surface. At present, the Sprayed FRP repair and strengthening method using the epoxy resin has not been fully discussed. In order to investigate the material property of Sprayed FRP, this study carried out tensile tests of the material specimens which are changed with the combinations of various variables such as the length of shot fiber and mixture ratio of shot fiber and resin. These variables are set to have the material strength equal to one layer of the FRP sheet. As a result, the optimal length of glass and carbon shot fibers were derived into 3.8cm, and the optimal mixture ratio was also deriver into 1:2 from each variable. And also, the thickness of Sprayed FRP to have the strength equal to one layer of FRP sheet was finally calculated.

• Clinics in Shoulder and Elbow
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• v.17 no.2
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• pp.91-100
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• 2014

Partial-thickness rotator cuff tear (PTRCT) is not single disease entity but one phase of disease spectrum. Symptoms of PTRCT vary from being asymptomatic to severe pain leading to deterioration in quality of life. Pathogenesis of degenerative PTRCT is multifactorial. Whereas articular sided PTRCT is usually caused by internal causes, both internal and external causes have important role in bursal sided PTRCT. A detailed history, clinical examination and magnetic resonance angiography are used in the diagnosis of PTRCT. Treatment of PTRCT is chosen based on age, demands of patients, causes and depth of tear. In most patients, non-operative treatment should be initiated. Whereas debridement can be done for less than 6 mm of articular sided PTRCT and in less than 3 mm of bursal sided PTRCT, repair techniques should be considered for higher grade PTRCT than that. Although the effect of acromioplasty is not clear, acromioplasty may be performed when the extrinsic causes appear to be the cause of tear. Either transtendon repair technique or repair after tear completion provided satisfactory clinical outcomes in treatment of articular sided PTRCT.

• Journal of Surface Science and Engineering
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• v.56 no.4
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• pp.283-287
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• 2023

The structures for road safety are guard rails that protect the cars and passengers. If an accident occurs on the roads after a long period of installation, it may escalate into a major disaster. In order to repair many guard rails, the existing repair method of replacing them with new ones requires enormous financial resources. To solve this problem, the G-SAVE method was developed to repair the guard rail without replacing them. This method removes the rust on the surface of the guard rail and then performs ambient-dip galvanizing coating on it without replacing the new ones. No studies or reports have yet been made on the risk assessment of harmful substances, vehicles for these entire processes. Therefore, this paper focuses on risk assessment using the PHA (Preliminary Hazard Analysis) technique and conducts risk assessment for concept design stage of the coating vehicles.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.189-196
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• 1984

Although the conventional methods of cardiopulmonary bypass for open heart surgery have been employed, it has been usual method to repair of congenital heart disease in infancy using deep hypother-mia and circulatory arrest technique. In 1980, we reported total correction of congenital heart disease using surface induced hypothermia-total circulatory arrest and rewarming with limited cardiopulmonary bypass. in 1981, three patients below 10 kilogram, who had ASD and PDA, and two of VSD with pulmonary hypertension were operated on using simple deep hypothermia without cardiopulmonary bypass. During surface cooling, there were no ventricular fibrillation and arrhythmia. There were no difficulties to resuscitate the heart. Postoperative respiratory and neurologic complication were not occurred. Follow up examination for two to three years gave no evidence of cerebral damage due to circulatory arrest.

• Journal of Korean Neurosurgical Society
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• v.55 no.6
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• pp.353-356
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• 2014

The Sundt encircling clip was developed to repair defects of the vessel wall. With the advent of microvascular techniques, most parts of the damaged vessel wall during aneurysm surgery can be repaired by primary closure or by the bypass technique. However, these methods are not always successful. Here, we illustrate two cases of surgical clipping with the Sundt encircling clip in the ruptured internal carotid artery trunk aneurysm. The Sundt clip provides prompt control of unexpected tearing of the vessel wall or aneurysm and plays an important role in vascular rescue during aneurysm surgery.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.309-314
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• 2004

This study focused on the introduction of damage repair for polymeric composite carbody. called selfing tech-healinique. using microcapsules loaded with the healing agent The manufacturing process for microcapsules with the healing agent was introduced and tile characteristics of microcapsules manufactured by varying with various manufacturing process variables were evaluated. The DCPD was used for the healing agent and microcapsules were made of urea-formaldehyde resin. The magnitude and the size distribution of microcapsules were measured by a particle size analyzer using laser diffraction technique. Thermal stability was investigated by using a TGA under continuous and isothermal heating conditions for the healing agent. microcapsules without the healing agent. microcapsules with the healing agent.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.124-124
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• 2002

In order to determine the effect of the DNA repair inhibitors, cytosine arabinoside(Ara C)and 3-aminobenzamide(3AB) on the frequenceis of chromosomal aberrations and micronuclei induced by radiation. After in vitro exposure of human lymphocytes to x-ray(1-3Gy) DNA repair inhibitors, Ara C and 3AB were treated and the frequencies of micronuclei, translocation and dicentric chromosomes were analysed using FISH technique with DNA probe for chromosome 4.(omitted)

• Journal of Chest Surgery
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• v.25 no.6
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• pp.605-610
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• 1992

Improving intraoperative and postoperative myocardial protection and better construction and design of valvular prosthesis has reduced the mortality of MVR. But, ventricular rupture after MVR occurred occasionally and represented a potentially lethal complication. Transverse midventricular disruption presented as refractory myocardial failure immediately on termination of bypass or later often on initial period of good hemadynamics. From Jan., 1985 through Dec., 1991 131 MVRs were performed as isolated or combined procedures. Rupture of the posterior wall of left ventricle was observed in 2 patients. There were 2 type III ruptures Prevention is of utmost importance, and by taking certain precautions, the chance of ventricular rupture can be reduced. Repair should always be done by patch technique in the aid of the use of cardiopulmonary bypass with cardioplegic arrest. When the laceration is in the middle of the posterior left ventricle, external repair with the pericardial patch can be attempted first.

• Clinics in Shoulder and Elbow
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• v.18 no.2
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• pp.113-118
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• 2015

Rotator cuff tear is a common reason for shoulder pain. Although the surgical technique of rotator cuff repair is developing, high retear rate requires additional supplementary methods. Among these supplementary methods, as a kind of biologic augmentation, platelet-rich plasma (PRP) has been spotlighted and has recently been studied by many researchers. PRP, a concentrate of platelet extract obtained from whole blood, contains numerous growth factors. As this is known to play an important role in the tissue recovery process, it had been used for research in a variety of fields including orthopedics. Use of PRP has been attempted in surgical treatments of rotator cuff tear for better results; however, only a few large-scale research studies on the effect of PRP have been reported. Clinical results of each study are also variable. Therefore research using large-scale randomized, double-blind trials should be conducted in order to prove the application range, safety, and clinical effects of PRP.