• Transactions on Electrical and Electronic Materials
• /
• 제10권1호
• /
• pp.9-15
• /
• 2009

There is a growing demand for a high voltage silicone rubber composite with high mechanical property and high electrical property. The effect of modified cross-linking agent on the mechanical, electrical properties, and short-circuit test performance of silicone rubber insulators have been investigated. To use base polymer, the various silicone polymers were prepared by the equilibrium polymerization. Aluminum trihydrate surface was treated by vinyl silane. Liquid silicone rubber nanocomposite was prepared from the compounding of VPMPS, HPDMS, catalyst, and alumina trihydrate modified with 1,3,5-trivinyl-l,3,5-trimethylcyclotrisiloxane. The mechanical property and electrical property for insulation materials were measured, indicating the high tensile strength and the good short-circuit property.

• Journal of Magnetics
• /
• 제16권4호
• /
• pp.403-407
• /
• 2011

Metal-insulator type, nano-granular soft magnetic films have been reviewed from the viewpoint of high frequency magnetic materials. The formation of nano-granular structure is related to the magnitude of heat of formation of intergranule materials. Variation of the ratio of granule phase to intergranule phase in the film is found to produce various characteristics in the magnetic properties of the film. The HRTEM observation reveals that neighboring granules in the film with above 60 at.% Co, contact at considerable points and the films show soft magnetic properties which are explainable in terms of the random anisotropy model for nano-crystalline materials. Addition of Ni group elements in Co-O based films enhances their anisotropy field up to 400 Oe and they exhibit excellent frequency response of permeability. Also, large electromagnetic noise suppression effect is demonstrated as one of their potential applications.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 하계학술대회 논문집 C
• /
• pp.1292-1294
• /
• 1994

With the contact angle of phase epoxy resin on the inorganic filler(glass plate) surface treated with air plasma, we have studied about the interface between epoxy resin and glass plate as simple model of a glass fiber reinforced composite materials. The contact angle on the inorganic filler surface varied with surface treatment conditions. The contact angle significantly depends on plasma treating time and environment temperature of the oven.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1313-1314
• /
• 2006

For improvement of wear resistance property of atmospheric thermal plasma sprayed molybdenum (Mo) coating, diamond deposition on the atmospheric plasma sprayed molybdenum coating by the combustion flame chemical vapor deposition (CFCVD) has been operated. In this study, to diminish the thermal damage of the substrate during operation, a thermal insulator was equipped between substrate and water-cooled substrate holder. Consequently, diamond particles could be created on the Mo coating without fracture and peeling off. From these results, it was found that this process had a high potential in order to improve wear resistance of thermal sprayed coating.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1602-1604
• /
• 2000

When insulators are operated near cement factories, some amount of cement powder may be stuck on the surface of insulators and decreases their electrical performances. Three kinds of insulators, such as, silicone EPDM and porcelain insulators, are tested in this paper. Testing Voltage of 25kV is applied to the samples, and surface leakage current is measured for 6 months after cement solvent of 10 vol% was stuck on the surface of each insulator in the laboratory. Insulation layers are cut from 3 and 6 month-aged insulators and tested for ac breakdown, impulse breakdown, contact angle. After aging, electrical properties are unchanged in silicone and EPDM insulators but show some changes in porcelain insulators.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 하계학술대회 논문집 B
• /
• pp.1233-1235
• /
• 1993

With the Contact angle of phase epoxy resin on the inorganic filler(glass plate) surface treated with air plasma, we have studied about the interface between epoxy resin and glass plate as simple model of a glass fiber reinforced composite materials. The contact angle on the inorganic filler surface varied with ambient temperature and surface treatment conditions.

• 전기학회논문지
• /
• 제56권8호
• /
• pp.1471-1475
• /
• 2007

In this paper, a novel embedded ultra wideband (UWB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (${\varepsilon}_r=30$) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator-metal (MIM) capacitor. In order to obtain excellent attenuation characteristics by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size ($3.7{\times}4{\times}0.77\;mm^3$) which is compatible with LTCC devices.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 추계 학술논문 발표대회
• /
• pp.130-131
• /
• 2019

As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. In addition, the conventional styrofoam insulating material has a problem that the thickness of the heat insulating material to achieve a standard heat permeability is rapidly increased. Due to the thick insulation, there is a high risk of spreading vulnerable structures such as fire due to lack of space between buildings. On the other hand, the method of using the insulation as a formwork is known to be excellent cost saving effect through the reduction of the formwork usage and the simplification of the external insulation work. In order to solve this problem, this study aims to fabricate a multi-layered insulator that combines high-performance phenolic foam insulation and styrofoam insulation and evaluate the deflection characteristics for use as formwork.

• 한국전자파학회논문지
• /
• 제21권6호
• /
• pp.583-590
• /
• 2010

본 논문에서는 제어 가능한 전송 영점을 갖는 새로운 Composite Right/Left Handed(CRLH) 전송 선로가 제안 되었다. 제안된 CRLH 전송 선로의 단위 셀은 MIM 형태의 커패시터와 마이크로스트립 스터브 인덕터와 co-planar waveguide(CPW) 인덕터로 구성되어 있다. 또한 제안된 전송 선로는 각각의 단위 셀의 MIM 커패시터와 마이크로스트립 스터브 인덕터에서 발생하는 전자기 결합 성분에 의해 차단 대역에 두 개의 전송 영점이 발생한다. 제안된 전송 영점을 갖는 CRLH 전송 선로의 응용으로 UWB 시스템을 위한 광대역 통과 필터를 설계 및 제작하였다. 측정 결과, 통과 대역의 하측과 상측에 전송 영점이 발생하는 것을 확인하였으며, 대역 통과 필터의 급전 구조를 제외한 크기는 8 mm$\times$8 mm으로 $\lambda_g$/4 이하의 전기적 크기를 갖는다.

• Composites Research
• /
• 제17권3호
• /
• pp.15-22
• /
• 2004

위성 발사체의 추진 기관에 의한 음향 하중은 이륙 시 작용하는 주요한 동적 하중 중 하나로서, 이에 의한 위성이나 탑재물의 파손이 보고되고 있다. 위성이나 탑재물에 작용하는 음향 하중의 강토를 저감하기 위해서는 노즈 페어링의 구조 설계 시 차음 성능을 고려한 설계가 필요하다. 특히 복합재 구조의 경우 금속재 구조에 비해 비강성이 커서 음향 하중의 차음 측면에서는 불리하다. 본 논문에서는 위성 발사체의 노즈 페어링용 복합재 평판의 차음 특성을 살펴보았다. 노즈 페어링 구조로 사용 가능한 4종의 복합재 구조에 대하여 무한판 이론 및 통계적 에너지 해석법(SEA)을 이용하여 차음 성능을 평가하였다. 해석 결과를 토대로 두 종류의 복합재 평판을 제작하여 이에 대한 차음 성능을 측정하고 예측치와 비교를 수행하였다. 이를 바탕으로 무게 대비 차음 성능이 우수한 노즈 페어링용 복합재 구조를 선정할 수 있었다.