• Composites Research
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• v.22 no.4
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• pp.33-40
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• 2009

Fiber orientation effects on the impact surface fracture of the glass plates coated with the glass fiber/epoxy lamina layer were investigated using a small-diameter steel-ball impact experiment. Four kinds of materials were used: soda-lime glass plates, unidirectional glass fiber/epoxy layer(one ply, two plies)-coated, crossed glass tiber/epoxy layer (two plies)-coated glass plates. The maximum stress and absorbed fracture energy were measured on the back surface of glass plates during the impact. With increasing impact velocity, various surface cracks such as ring, cone, radial and lateral cracks appeared near the impacted site of glass plates. Cracks in the plate drastically diminished by glass fiber coating. The tiber orientation guided the directions of delamination and plastic deformation zones between the tiber layer and the glass plate. Impact surface-fracture indices expressed in terms of the maximum stress and absorbed energy could be used as an effective evaluation parameter of the surface resistance.

• Composites Research
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• v.13 no.4
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• pp.75-82
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• 2000

A small diameter steel-ball impact experiment was performed to study the impact resistance of the surface of glass plates bonded with glass fabric/epoxy lamina. Five kinds of materials were used in this study: soda-lime glass plates, glass/epoxy lamina(one layer)-bonded and unbonded glass plates, glass/epoxy lamina(three layers)-bonded and unbonded glass plates. The range of impact velocity was 40 120m/s. The maximum stress and absorbed fracture energy were measured on the back surface of glass plates. With increasing impact velocity, various types of surface cracks such as ring, cone, radial and lateral cracks took place in the interior near the impacted site of glass plates. The cracks drastically decreased with glass/epoxy lamina coating. The surface fracture behavior could be evaluated using the maximum stress and the absorbed fracture energy.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.130-130
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• 2016

본 연구는 다양한 전산도와 유리산도 간의 산비에 따른 인산-망간 화성처리를 바탕으로 각 산비 조건에 따른 피막특성을 SEM과 EDAX로 확인 하였다. 더불어 내마모특성을 확인하고자 내마모시험을 통해 산비 조건에 따른 피막의 마찰계수를 확인하여 분석결과를 토대로 인산-망간 화성처리의 최적 산비를 도출하였다. 그 결과 산비 7.3 부근에서 최적의 표면 및 기계적 특성을 확보하였으며, 산비가 8.4로 지나치게 높거나, 산비가 6.0으로 떨어지게 되면 유리산도가 지나치게 높으면 피막 생성속도 및 결정성이 저하되어 위의 특성이 저하됨을 알 수 있었다.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.43-54
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• 1995

This study was conducted to examine the metal release of TiN-plated stainless steel orthodontic appliances by constructing the simulated orthodontic appliances equivalent to maxillary half arch, by dividing into TiN-plated and TiN-nonplated Bloops and by dividing again these groups into welded and nonwelded groups. And then, the total quantity of metal release was obtained by measuring the amounts of both soluble and precipitated nickel and chromium after immersing in artificial saliva for 15 days. And then, the corrosion appearance of surface structure was observed by using SEM. The results of this study were summarized as follows. 1. The total amounts of released nickel and chromium showed that the TiN-plated group after welding(Group 1) was 25.46 ${\mu}g$, respectively, and 17.4 ${\mu}g$, while the TiN-nonplated group after welding(Group III) was 54.69 ${\mu}g$, respectively, and 85.27 ${\mu}g$. Then, the TiN-Plated group indicated less amounts of metal release(p<0.05). 2. The total amounts of the TiN-plated group without welding(Group II) was 0.05${\mu}g$ and 0.34${\mu}g$, respectively. Then, it was shown that the TiN-plated group without welding(Group II) indicated less metal release than that of the TiN-Plated group after welding(Group I)(p<0.01, p<0.05). 3. When observing their surface structure, there were a lot of precipitate and pitting corrosion in the groups with welding(Group I & III), when the TiN-plated group(Group I) showed lower level than the TiN-nonplated group(Group IIII). On the other hand, the groups without welding(Group II & IV) indicated a little of pitting corrosion. 4. In case of observation with the naked eyes, it was shown that there were significant disco1oration and corrosion in the groups with welding(Group I & III), while there was no any remarkable change in the groups without welding(Group II & IV).

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.171-176
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• 1997

Th-232를 Fertile로 사용한 핵연료는 U-238을 Fertile로 사용한 핵연료보다 핵확산 저항성, 방사성 폐기물 생성면에서 유리하다. 본 연구에서는 MHTGR의 핵연료에 사용된 탄소피막 입자 기술을 토륨 핵연료에 적용하여 새로운 가압경수로용 핵연료로 개념 설계하였다. 핵연료의 설계안을 울진 3,4호기 집합체 설계안에 적용하여 해적 타당성을 살펴보았다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.201-201
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• 2011

크롬대체도금으로 개발 추진되고 있는 전기Ni-W합금도금피막은 경질크롬 도금피막보다도 고온에서 경도 및 내 산성이 우수하고, 유리성형용 금형으로 사용되고 있다. 최근 일본에서는 지금까지의 무전해Ni-W-P합금피막에 비해서 텅스텐, 인의 함유율이 높고, 질산 이외의 염산, 황산의 산성 환경과 암모니아, 수산화나트륨 등의 알칼리성 환경에서도 부식이나 변색이 생기지 않는 무전해Ni-W-P합금도금기술을 크롬도금을 대체하는 도금으로서 개발하고 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.137-138
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• 2015

Ni-W 합금도금은 내마모성, 내산성 및 내열성 등의 여러 특성을 가지며 높은 피막경도도 안정하게 얻어지기 때문에 경질 Cr 도금의 대체도금으로서 유리 성형용 금형, 롤러 표면재료, 자동차 접동부품 등 다양한 공업 분야와 제품에 적용되고 있다. Ni-W 합금도금은 도금액 및 전해조건에 따라서 도금 피막에 균열이 생기는 경우가 있다. 도금 피막의 균열 발생요인으로서 도금재료의 환경온도에 의한 열응력, 도금 피막과 기재와의 팽창 수축 차이에 의한 영향을 생각할 수 있다. 도금 내부응력의 발생이유로서 공석한 수소의 이탈설, 결정합체설, 이외에 과잉 에너지설 및 결자결함설도 제안되고 있다.

• Composites Research
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• v.31 no.6
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• pp.332-339
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• 2018

Fiber metal hybrid laminate (FML) can be used as an economic material with superior mechanical properties and light weight than conventional metal by bonding of metal and FRP. However, there are disadvantages that it is difficult to predict fracture behavior because of the large difference in properties depending on the type of fiber and lamination conditions. In this paper, we study the failure behavior of hybrid materials with laminated glass fiber reinforced plastics (GFRP, GEP118, woven type) in Al6061-T6 alloy. The Al alloys were coated with GFRP 1, 3, and 5 layers, and fracture behavior was analyzed by using a static test and a low cycle fatigue test. In the low cycle fatigue test, strain - life analysis and the total strain energy density method were used to analyze and predict the fatigue life. The Al alloy did not have tensile properties strengthening effect due to the GFRP coating. The fatigue hysteresis geometry followed the behavior of the Al alloy, the base material, regardless of the GFRP coating and number of coatings. As a result of the low cycle fatigue test, the fatigue strength was increased by the coating of GFRP, but it did not increase proportionally with the number of GFRP layers.

• Journal of the Korean Institute of Telematics and Electronics
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• v.4 no.1
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• pp.3-12
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• 1967

This study has been endeavored to deposit resistance films of tin oxide on the cylindrical Pyrex glass rods. In this report, at first an outline of the film formation is described and later some electrical properities of the resistance films manufactured through new method is discussed in detail. Because the new method which is called, "Chemical Vapour Reaction Process", is not only easy to get stable resistance films, but also doesn't need vacuum systtem, it seems to be a promising fundamental process to go into flow system mass production. Electrical properties of resistance films made by the new mathod are similar to or surpassing those by provious method (for example splay method). The top data thus obtained shows that surface resistivity is 25ohm/sq. with 12 ppm in temperature coefficient of resistor. resistor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.648-652
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• 2002

Removing shup from oyster by aeration method and coating with edible coating materials were investigated to improve oyster quality for the retort processing. Aeration rate and pore size of nozzle were critical factors to remove shup by aeration method. Optimum aeration rate and nozzle size were 45 L/min and 0.4 mm, respectively, when aeration was peformed two times and each operation maintained for 1 minute. Sodium alginate (SA) was used for oyster as the basal coating material. However, SA affected mouth-feel when it was applied at high concentrations. Sub-coating materials including skim milk, waxy corn starch, Purity CSC, white corn starch and carboxymethylcellulose (CMC) in decreasing order showed a positive effect on improving coatability and mouth-feel. Therefore, it is suggested that 1.5% SA and 0.9% skim milk should be the optimum composition of coating materials for oyster. Browning and syneresis of the porridge containing the coated oyster were considerably inhibited as compared with the sample without the coated oyster.