• The Academic Congress of Korean Shoulder and Elbow Society
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• 2007.03a
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• pp.106-106
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• 2007

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.186-186
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• 2009

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.184-184
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• 2009

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.5-5
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• 2009

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.355-358
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• 1999

In recent times, large strands have become increasingly popular in the pretensioned prestressed industry and have found wide applications in varying geometries of sections. However, use of such elements and their behavior in several situations have been questioned with respect to anchoring of these strands in concrete. In addition, the experimental results available on bond are limited and information relating to large strands is rare. This study was conducted to determine the influence of some of the inadequately examined properties on transfer length of prestressing strand. The principle variables considered were strand size, concrete strength and clear bottom cover. The experimental results indicate clearly that concrete strength at transfer and cover size influence transfer length significantly. An attempt was made to suggest prediction equation for transfer length including above parameters.

• Journal of the Korean Society of Safety
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• v.15 no.3
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• pp.102-107
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• 2000

The extensive use of pretensioned prestressed concrete in the modem construction industry, together with wider application of pretensioned components for structural purposes requires some important consideration on the adequate transfer of prestress force into the concrete, especially around the end zones of pretensioned member. The main objective of this paper is to study the effects of various important parameters on the bond characteristics of prestressing strand around the end zone of high strength pretensioned concrete members. To this end, a comprehensive experimental program has been set up. The principal test variables considered were strand diameter, concrete strength, concrete cover size. The present study provides valuable test data for the realistic and accurate determination of transfer length, which can be efficiently used for improving the design equation of transfer length in pretensioned prestressed concrete members.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.367-370
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• 1999

An experimental study was carried out to estimate development lengths of the prestressing strand in pretensioned beams. Recent studies had indicated that current desing provision were inadequate. Objective of this investigation is to determine the effect of strand diameter and concrete cover in pretensioned beams. Strand of the 1.52cm diameter is more useful and economic than that of the 12.7mm diameter, but current provision does not include 15.2mm diameter strand in experimental data. Because the property of strand has been developed, current provision need to be improved. Based on the experimental data, it was determined that bond failure would be prevented if no cracking occured in transfer zone of a pretensioned strand.

• The Journal of the Korean dental association
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• v.48 no.11
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• pp.798-802
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• 2010

Introduction: MTA has been studied for more than 15 years since it was introduced and developed at Loma Linda University. The purpose of this review was to present the current published papers regarding MTA's biologic properties and to provide a deep insight into the material's mechanisms of actions. Results: MTA has appeared to be biocompatible in many previous researches. In addition to that, it had a potential to increase cell reactions such as proliferation and differentiation, Recently, MTA like new endodontic materials has been introduced and marketed. Conclusions: On the basis of current evidences, MT A seems to be biocompatible. Meticulous studies need to be performed to adopt new endodontic materials into clinical applications,

• The Journal of the Korean dental association
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• v.38 no.3 s.370
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• pp.288-292
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• 2000

Perhaps the most frustrating scenario in dentistry lies in the apparently well-instrumented and well-obturated tooth that, becomes symptomatic after treatment of shows a periapical lesion on recall examination. Conventional root canal treatment demands stringent adherence to asepsis, awareness of canal morphology, and mastery of a variety of clinical techniques. But the risk of endodontic failure does not end with canal obturation. The quality of the coronal restoration may have a greater bearing on the ultimate success of a case than the quality of the root canal treatment itself. This review of the endodontic literature will define coronal leakage, describe its influence on endodontic treatment failures, and make specific recommendations on prevention.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.204-207
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• 2002

주로 터널 등에 사용되는 숏크리트는 콘크리트와 달리 높은 압력으로 뿜어붙이기 때문에 콘크리트와 다른 역학적 특성이 보이게 된다. 그러나 국내에서는 이러한 숏크리트의 중요한 역학적 특성인 내구성능에 관한 실험이 미미한 실정으로 본 연구에서는 숏크리트 장비를 이용하여 실험시편을 급결제의 종류, 혼화제의 종류, 혼화재(실리카흄, 고로슬래그, 플라이애쉬)의 종류 등에 따라 제작하여 강도실험(28일 및 56일 압축강도, 28일 휨강도, 56일 할렬인장강도), 동결융해실험, 내투수성실험, 중성화실험 등의 폭 넓은 실험을 통해 고성능 숏크리트의 전반적인 내구특성을 규명할 수 있었다.(중략)