• Journal of the Korean Ceramic Society
• /
• v.42 no.2 s.273
• /
• pp.110-116
• /
• 2005

Suitable compositions which are sinterable at low temperature in the $BaO-B_{2}O_{3}-ZnO$ glass system were investigated as a function of the ratio between BaO and ZnO. The effect of $Al_{2}O_3$ filler on densification and physical characteristics of the glass was also examined. When the amount of $Al_{2}O_3$ filler increased, the densification rate and the values of dielectric constant, thermal expansion coefficient and hardness in the glass-filler composites decreased gradually. The decreasing rate of the physical properties accelerated when fine $Al_{2}O_3$ filler was used. However, the fracture toughness of the composite rather increased due to the existence of filler particles and pores which effectively suppressed crack propagation with addition of fine $Al_{2}O_3$ filler.

• 한국정보통신설비학회:학술대회논문집
• /
• 2004.08a
• /
• pp.19-22
• /
• 2004

위성 DMB(Digital Multimedia Broadcasting)는 위성을 통하여 이동 흑은 고정 무선 가입자 수신기에게 비디오 방송 및 정지화상 CD 음질의 오디오 방송과 각종 데이터 서비스와 같은 Multimedia 서비스를 제공하는 서비스이다. 향후 새로운 사업으로 다양한 부가가치를 이끌어 낼 것으로 기대를 받고 있다. 우리나라의 경우 위성 DMB기술기준으로 System E방식이 선정되었다. 본 논문에서는 위성DMB 서비스 의 음영지역을 해소하기 위해 사용되는 재생중계방식의 중계기인 Gap Filler 개발에 대해 기술한다. System E용 Cap Filler용 보조 방송의 전송 방식 선정과 보조방송에서 주 방송으로의 변환 기법, Gap Filler 망설계시에 고려해야 할 사항 등에 대해 기술한다.

• Proceedings of the KIEE Conference
• /
• 1996.11a
• /
• pp.209-211
• /
• 1996

The dielectric breakdown characteristics of DGEBA/MDA/SN system filled with $Al_2O_3$ under AC high electric field were investigated. As the filler content increased, the dielectric breakdown strength increased, but decreased at higher filler content than 5 phr. The probability of defects such as air bubbles, peel between filler and epoxy resin insulator, etc. increase proportionally to filler contents. Fillers blockade the treeing growth and relax the electric field at the tip of electrical tree and the treeing propagation rate decreases so that the strength showed higher strength at lower filler content than 5 phr.

• Elastomers and Composites
• /
• v.32 no.5
• /
• pp.295-301
• /
• 1997

The effects of filler types and compositions on the final properties such as tensile strength, % elongation, hardness, and specific gravity of chloroprene rubber were investigated. The fillers involved in this investigation were HAF-type carbon black, Mistron, and white clay, For each filler, the variation of filler compositions gave almost the linear effects on the all properties investigated. For a fixed filler composition, different filler types gave different influential strength on rubber properties. After linearlization of experimental data with respect to each filler composition, the simple linear addition of each property with respect to filler compositions was applied to predict the final properties of the filler included rubber systems. For the chloroprene rubber system including the fillers composed of Mistron(25phr)/HAF(20phr)/clay(35phr), the predicted properties were well in accordance with the experimental results. Similar results were obtained for other additives such as processing oil and accelerator.

• Elastomers and Composites
• /
• v.13 no.2
• /
• pp.99-107
• /
• 1978

The measurement of the infrared absorption spectrum of supporting reinforcing filler which is oltained from the domestic area of Korea, Japan and U.S.A., is used by the method of KBr pellet. As a result of experiment, each absorption fond of the filler had appeared differently, because of each filler is consisted of different chemical composition, different crystalline form, different method of preparation, and the different ways of use etc. According to the above phenomena, each filler seems to have a different characteristic infrared absorption band, We can find what filler is used for sample rubber.

• Elastomers and Composites
• /
• v.30 no.1
• /
• pp.9-19
• /
• 1995

To make filler loaded conducting rubber which has the excellent electronical and physical properties, CR and NBR were mixed with magnetite$(Fe_3O_4)$. From the result of the study, vulcanization characteristics shows the upgrading curve as increase in filler concentration and CR has more torque than NBR. When elongation be higher, modulus comes to decreases. Tear strength gradually decrease after showing of the maximum point when is in the 100phr in all. Resilience is not good to cause the increase in filler concentration. In the electrical properties, conductivity becomes smaller when filler concentration is increased. The increase of voltage makes an conductivity grown, but the changed rate is weak. The influence of temperature hardly changes on increasing temperature. The morphology and the distribution for a conductivity filler through SEM were better, the more filler concentration increase, the shorter the particle interval is.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2006.11a
• /
• pp.233-236
• /
• 2006

A dilatometer was used to investigate the effect of cure conditions and the presence of filler in an epoxy system. These studies showed shrinkage in the cured epoxy when heating it through the glass transition temperature region. The magnitude of the shrinkage, related to stress build up in the epoxy during curing, was influenced by the processing conditions, filler presence and the nature of the mold used to contain the resin. Cure and cyclic cure at a lower temperature, prior to a post cure, decreased the magnitude of observed shrinkage. Cure shrinkage decreased with number of cyclic cure. Post cured samples outside the mold led to less shrinkage compared with sample in the mold. And sample containing kaolin filler showed less shrinkage than unfilled sample.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.4
• /
• pp.1-5
• /
• 2009

A dilatometer was used to investigate the effect of cure conditions, mold types and the presence of filler in an epoxy system. These studies showed shrinkage in the cured epoxy when heating it through the glass transition temperature region. The magnitude of the shrinkage, related to stress build up in the epoxy during curing, was influenced by the processing conditions, filler presence and the nature of the mold used to contain the resin. Cure and cyclic cure at a lower temperature, prior to a post cure, decreased the magnitude of observed shrinkage. Cure shrinkage decreased with the number of cyclic cures. Post cured samples outside the mold led to less shrinkage compared with samples in the mold. Sample cured in a silicon mold represented less shrinkage than sample cured in an aluminum mold. Sample containing kaolin filler showed less shrinkage than unfilled sample.

• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.339-340
• /
• 2014

본 논문에서는 아답터의 크기를 소형화하기 위한 Active Valley Filler 플라이백 컨버터를 제안한다. 기존의 아답터에서 입력 전해 캐패시터는 전파 정류된 AC 전압($90{\sim}264V_{RMS}$)을 평활 시키고, 안정적으로 출력단에 에너지를 공급하기 위해 입력 에너지를 저장하는 수단으로 사용된다. 입력 전해 캐패시터는 마진이 고려되어야 하기 때문에 설계를 통해 구한 용량 및 내압보다 더 큰 값의 캐패시터가 사용되고, 이것은 아답터의 크기 증가로 이어진다. 반면, 제안 방식은 플라이백 컨버터의 입력단에 Active Valley Filler 회로를 적용하여 기존에 사용되었던 큰 크기의 입력 전해 캐패시터보다 작은 크기의 캐패시터를 사용할 수 있으므로 아답터의 소형화가 가능하다. 제안 방식의 타당성을 검증하기 위해 휴대폰 아답터용 10W급 플라이백 컨버터의 시작품을 제작하여 실험하고 그 결과를 제시한다.

• Journal of Welding and Joining
• /
• v.34 no.4
• /
• pp.1-8
• /
• 2016

Metal AM(Additive Manufacturing) has been steadily developed and that is classified into two method. PBF(Powder Bed Fusion) deposited in the bed by the laser or electron beam as a heat source of the powder material and DED(Directed Energy Deposition) deposited by varied heat source of powder and solid filler material. In the developed countries has been applying high productivity process of solid filler metal based DED method to the aerospace and defense sectors. The price of the powder material is quite expensive compared to the solid filler metal. A study on DED method that is based on a solid filler metal is increasing significantly although was low accuracy and degree of freedom.