• 한국안전학회지
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• 제15권1호
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• pp.86-92
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• 2000

Recently, more advanced electronic elements become, they consume powerful and radiate more heat in devices. So the most suitable packaging technique is keenly needed. The most important purpose of packaging is to protect devices within a system for a long time and to prevent life of devices from external environments; floating ions such as humidity or sodium, and exposure from ultraviolet rays. In order to study the electrical properties of silicone gels often used as packing material due to the curing condition, volume resistivity and AC breakdown experiment are performed. Specimens are made up at several cured times and temperatures condition ; 0.5[H], 1[H] and 2[H] at 100[$^{\circ}C$], 125[$^{\circ}C$], 150[$^{\circ}C$], 160[$^{\circ}C$], 170[$^{\circ}C$] and 180[$^{\circ}C$]. It is confirmed that from volume resistivity experiment liquid silicone become get state at 90~100 [$^{\circ}C$] and cured specimen for 1~2[H] at 170[$^{\circ}C$] are superior in electrical properties.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.172-177
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• 1999

In this paper, the physical and electrical properties of the synthetic fluids No. 2 class Ⅶ used the insulating oils for automobile ignition coil are studied. Also, benzotriazole(BTA) as the streaming electrification suppressant additive is added to the oil, and the change of physical and electrical properties due to different BTA concentration is investigated. To investigate the electrical characteristics, the breakdown strength of each specimen by an experiment for AC breakdown and the changes of conductivity by measuring volume resistivity are analyzed. It is considered that the effective content of BTA as charge suppressant additive is about 10[ppm] from the results of AC breakdown and volume resistivity test.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권8호
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• pp.455-461
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• 2000

The inhibiting effects of electrical treeing and insulation properties of LDPE contained with treeing inhibitors was studied under radiation environment. Barbituric acid and its derivatives were selected as treeing inhibitors. The inception voltage and growth of tree, AC breakdown strength, volume resistivity, high frequency capacitance, and dissipation factor were observed as a function of dose(up to 1000 kGy). And also, measurements of thermo-luminescence(TL), and gel content were carried out. Crosslinked low density polyethylene(XLPE) contained with treeing inhibitors shows better insulation characteristics such as electrical tree propagation, AC breakdown strength, and volume resistivity than those of pure LDPE. The most effective treeing inhibitor was found on the barbituric acid contained XLPE.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.217-223
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• 1995

In this paper, we investigated physical properties and electrical characteristics of the fluorocarbon that used as coolants for large power gas-insulated transformer. Volume resistivity of the fluorocarbon was .rho.=1.87*10$^{15}$ [.ohm.cm] at 1 atm, 27.deg. C. Dielectric constant was 1.86 and decreases as temperature increase. The breakdown voltage at 1 atm was higher than that of transformer oil. The breakdown voltage of fluorocarbon vapor was about 18kV when pressure in a test chamber increases over lkg/cm$^{2}$. When fluorocarbon was mixed with SF$_{6}$ gas, breakdown voltage of the mixed was higher than that of fluorocarbon. Then fluorocarbon leads to increase over 4kg/cm$^{2}$ in pressure as temperature increase. Therefore, when a gas-insulated transformer is manufactured, the design must be taken into consideration a high-pressure.

• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.756-762
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• 1997

In this paper the change of electrical properties of transformer oil due to electron beam irradiation is investigated. The specimens are produced with a some different dose of 0.5[Mrad], 1[Mrad] and 2[Mard] except for original specimen. The physical properties of each specimen is analyzed by using the FT-IR spectrum. So it is confirmed that carbonyl groups are increased according to the increase of electron beam dose and also that the nitric compounds are disappeared. The magnitude of dielectric dissipation factor appears maximum value by the contribution of dipoles and ions in the low temperature low voltage region and it is stable due to the saturation of carriers in the high temperature high voltage region in the electric conduction characteristics. Volume resistivity is also measured one of original specimen is larger than irradiated specimen.

• 한국재료학회지
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• 제17권4호
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• pp.232-235
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• 2007

Indium tin oxide (ITO) films were deposited on polycarbonate CR39 substrate using DC magnetron sputtering. ITO thin films were deposited at room temperature because glass-transition temperature of CR39 substrate is $130^{circ}C$ ITO thin films are used as bottom and top electrodes and for organic thin film transparent transistor (OTFT). The electrodes electrical properties of ITO thin films and their optical transparency properties in the visible wavelength range (300-800 nm) strongly depend on the volume of oxygen percent. The optimum resistivity and transparency of ITO thin film electrode was achieved with a 75 W plasma power, 10 % volume of oxygen and a 27 nm/min deposition rate. Above 85% transparency in the visible wavelength range (300-800 nm) was measured without post annealing process, and resistivity as low as $9.83{\times}^{TM}10^{-4}{\Omega}$ cm was measured at thickness of 300 nm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.591-593
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• 2003

Silicone composites for high voltage insulator(HVI SC) were prepared by adding aluminum trihydrate(ATH) treated by surface treatment agent to base silicone compound at the ratio of 100:20, 100:40, 100:60, 100:80, and 100:100, respectively. And also, ATH was treated by various surface treatment agents, such as stearic acid, acryl silane vinyl silane under compounding process. electrical properties were investigated for the various contents of ATH and solace-treatment agents we mlas ured volume resistivity, breakdown and tracking resistance were for HVISC containing ATH treated by viuyl silane.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.61-63
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• 1988

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 3차
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• pp.24-30
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• 2010

The void ratio and elastic moduli are design parameters used in geotechnical engineering to understand soil behavior. Elastic and electromagnetic waves have been used to evaluate the various soil characteristics due to high resolution. The objective of this study is to evaluate the void ratio and elastic moduli based on elastic wave velocities and electrical resistivity. The Field Velocity Resistivity Probe (FVRP) is developed to obtain the elastic and electromagnetic wave profiles of soil during penetration. The Piezoelectric Disk Elements (PDE) and Bender Elements (BE) are used as transducers for measuring the elastic wave velocities such as compressional and shear wave velocities. The Electrical Resistivity Probe (ERP) is also installed for capturing the electrical resistivity profile. The application test is carried out on the southern coast of the Korean peninsula. The field tests are performed at a depth of 6~20 m, at 10 cm intervals for measuring elastic wave velocities and at 0.5cm intervals for measuring electrical resistivity. The elastic moduli such as constraint and shear moduli are calculated by using measured elastic wave velocities. The void ratios are also evaluated based on the elastic wave velocities and the electrical resistivity. Furthermore, the converted void ratios by using FVRP are compared with the volumetric void ratio obtained by a standard consolidation test. The comparison shows that the void ratios based on the FVPR match the volume based void ratio well. This study suggests that the FVRP may be a useful device to effectively determine the elastic moduli and void ratio in the field.

• 폴리머
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• 제31권2호
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• pp.117-122
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• 2007

본 연구에서는 제자리 중합에 의해 합성된 기상성장 탄소나노섬유/폴리이미드(VGCNFs/PI) 복합재료 필름의 기계적, 전기적 특성과 열안정성을 만능재료 시험기와 체적저항기, 열중량분석기를 통해 관찰하였다. 그 결과, VGCNFs 일정량 첨가되었을 때 복합재료 필름의 인장강도가 증가한 것을 관찰할 수 있었다. VGCNFs/PI 복합재료 필름의 체적저항 값은 VGCNFs 첨가량이 증가할수록 감소하였으며, 전기적 percolation threshold는 VGCNFs 함량 1과 3 wt% 형성되었는데, 이는 복합재료 내부에서 VGCNFs 상호간 네트워크의 형성으로 인하여 전기적 경로가 만들어졌기 때문이라 판단된다. VGCNFs가 PI 복합재료 필름의 열안정성은 순수한 이미드 필름보다 VGCNFs가 첨가됨에 따라 향상되었으며, 이는 충전제로 사용한 VGCNFs가 PI 수지에 잘 분간됨에 따라 복합재료의 가교화에 영향을 주어 VGCNFs/PI 복합재료 필름의 열안정성이 향상된 것으로 판단된다.