• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.333-335
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• 2014

20년 이상의 에이징 테스트와 브레이킹 테스트를 걸친 모빌리스 부이는 해상에서 저항력이 강한 특수 폴리에틸렌 재질로 제작된다. 국제항로표지협회 (IALA AISM)에서 공식 계류라인 소프트웨어로 선정한 CALMAR를 직접 개발함으로써 기존 강철 부이에 비해 우월한 안전성과 긴 수명, 간단한 유지보수, 현저한 유지비용 감소 등 다양한 장점을 지니고 있다. 전 세계적인 부이 사용의 추세가 변화됨에 따라 국내에도 보다 좋은 해양발전을 위해 플라스틱 부이를 소개한다.

• Journal of the Korean Chemical Society
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• v.21 no.5
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• pp.384-388
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• 1977

Clay-polymer thickened greases were made by dispersing bentone-polyethylene and bentone-atactic polypropylene into mineral oil at an adequate temperature, and the physical properties such as wear and water washout characteristics, oxidation and shear stabilities, and dropping point of the greases were tested. Even if the greases failed to meet some properties, it was found that those greases can be used for some special purposes, by observing and comparing the properties with those of clay-metallic soap thickened greases that were made in this experiment.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.526-531
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• 2010

Early childhood caries which mainly affect maxillary anterior area, defined as 'the presence of 1 or more decayed, missing, or filled tooth surfaces in any primary tooth in a child 71 months of age or younger'. Extraction of teeth when early childhood caries affected in maxillary primary incisors often develops progressively, result in severe destruction of crowns, acute or chronic pulpitis, and periapical abscess formation. Maxillary primary incisors are need to preserve as possible, because the early loss of maxillary primary incisors may lead to various functional, esthetical, and psychological problems. It is necessary to the availability of an easy to perform technique capable of providing efficient, durable, functional, and esthetic restorative methods. Polyethylene fiber-reinforced post can be used in strengthen of composite resins that is esthetic and good physical and mechanical properties. $Ribbond^{(R)}$ is made from an polyethylene fiber, has numerous usages, its surface is treated to enhance adhesion to resins, ease of manipulation, relatively cost effective. We report this case, had restored of maxillary primary incisors with severe coronal destruction due to affecting severe early childhood caries, using polyethylene fiber-reinforced posts, composite resin cores, and celluloid crowns. We could obtain good result of treatment.

• Journal of the Korean Geosynthetics Society
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• v.2 no.3
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• pp.19-24
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• 2003

Long-term performance of smooth and textured type HDPE geomembranes which were used to the liner and slope systems of waste landfills was examined. Artificial surface defects were added to the surface of geomembranes by scratch addition apparatus specially designed. The mechanical and frictional properties, chemical and ultra violet light resistances and oxidative induction time(OIT) of geomembranes were examined for the cases of defective/non-defective surfaces. Frictional properties of textured type geomembranes showed more excellent than those of smooth type geomembranes. Finally, it was known that the long-term performance of non-defective and textured geomembranes was better than that of defective geomembranes through chemical and UV resistance and OIT tests etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.426-433
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• 2019

After an earthquake, fire and gas explosions are more likely to cause more casualties in cities with many apartment buildings and large complex buildings. In order to prevent this, seismic design is necessary for the fire protection sprinkler system. However, most systems currently use stainless-steel pipes, although synthetic resin pipes are used in some special places. These materials are susceptible to vibration and earthquakes. This study evaluated the displacement absorption flexibility of polyethylene (PE) and aluminum (Al) multi-layered composite pipes to increase the seismic performance in a vibration environment and during earthquakes. The seismic performance was compared with that of a stainless-steel and PE pipes. The seismic characteristics can be measured by measuring the amount and extent of vibration transmitted by the sprinkler pipe. This method can be used to judge the seismic characteristics to attenuate the vibration during an earthquake. The seismic characteristics of the pipe were verified by comparing the logarithmic attenuation rate to the initial response displacement of the vibration generated by the transverse vibration measurement method.