• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.93-96
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• 2008

500나노 입자 및 기본 물성이 우수한 이중층상구조금속수화물(LDH)를 합성하고 PVC 수지에 적용하여 고온, 저온열안정성 및 가공특성으로 인장강도, 신율, 체적저항 등이 우수한 시제품을 합성한 후 개발한 이중층상구조금속수화물(LDH) 시제품을 사용하여 무독성안정제(금속석검계), 내외부활제류, 가공조제, 산화방지제 등 기타 첨가제 등을 사용하여 PVC수지에 적용하여 수지배합에 따른 시험편을 제작하여 배합비별로 고온, 및 저온열안정성, 체적고유저항, 가공성(인장강도, 신율 등), 내후성, 초기 착색성 등 물성, 기계적 가공특성 및 성능이 우수한 할로겐수지용 무독성배합을 개발한다. 최종적으로 개발한 이중층상구조금속수화물(LDH)을 사용하여 제조하여 PVC 수지의 열안정성 및 기계적 가공특성이 우수한 중금속계대체용 무독성복합열안정제를 개발하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.2
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• pp.32-39
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• 2005

The effectiveness of the pogo suppression device (PSD) on the response of the piping system simulating the fuel (or oxidizer) supply lines of the rocket engines was investigated. The system response defined as the ratio of the flow rate to the pressure in the main tube was obtained for various PSD gas volumes $((0\~2)\times10^{-3}m^3)$ and three different baffle hole diameters (5, 50, 115mm). Existence of a gas volume in the PSD reduced the system resonance frequency. With a larger gas volume, the resonance frequency became lower, but only slightly, while the fluctuations of the main tube pressure and the flow rate damped down considerably. The resonance frequency decreased with the increase of the PSD inlet restriction (or the decrease of the baffle hole diameter), though slightly. However, with a larger inlet restriction, the PSD pressure wave showed a delayed response with the smaller amplitude compared to the pressure variation in the main tube.

• Elastomers and Composites
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• v.38 no.3
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• pp.235-242
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• 2003

A vulcanization reaction characteristics of an isoprene rubber (IR)-modified natural rubber/carbon black (NR/CB) composite was studied using in-situ electrical property measuring technique. Since the electrical conductivity of the sample composite would be changed continuously during the vulcanization reaction by rearranging of the carbon black particles within the sample, volume resistivity (${\rho}$) might be obtained as a function or reaction time. A stabilization time ($t_i$), maximum reaction speed time ($t_p$), and volume resistivity at that time(${\rho}_p$) were defined from the data for the Arrhenius analysis. Volume resistivity ${\rho}$ showed a comparatively high value of ${\sim}10^8$ order before the reaction started, and dramatically decreased to be stabilized within $1{\sim}2$ minutes as soon as the reaction started. As the more time elapsed, thereafter, ${\rho}$ decreased monotonously to a certain constant value through a peak, ${\rho}_p$ at time $t_p$, which was considered as the maximum reaction rate. As a result, while $t_i$ values were comparatively constant as $1{\sim}2$ minutes, $t_p$ values showed to become shorter and shorter as the reaction temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.153-153
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• 2009

In the study the volume resistivity Characteristics of epoxy resin using nano and micro filler, nano and micro filler are made from insulating material epoxy resin using for transformer equipment and molding several devices as changing amount of addition of diameter 12 [nm] and 7 [${\mu}m$] $SiO_2$, we measured volume resistivity of nano and micro filler by High Resistance Meter(4329A). As the result of measurement, When is micro filler, the volume resistivity continuously increased over 80 [$^{\circ}$].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.195-198
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• 1998

In this paper, the physical and the volume resistivity properties due to linear low density polyethylene(LLDPE)/ethylene vinyl acetate(EVA) blends are studied. In order to measure the volume resistivity properties. the micro electrometer is used, the range of temperature and applying voltage are 25 to 120[$^{\circ}C$], form 100 to 1000[V] respectively. From FT-IR spectrum, LLDPE blended with EVA shows an absence of carbonyl and ether groups. From the experimental result of the volume resistivity properties, it is confirmed that the volume resistivity is decreased, which was attributed to the increase of molecular motions with the increase of temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.162-166
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• 1998

Synthetic fluid, class 7 group 2, as an insulating and cooling material is selected as. specimen, arid it is studied for the physical and electrical properties. Also, Benzotriazole(following as BT A) known as a suppressant of streaming electrification is added to it, and the change of physical and electrical properties by addition of BT A is investigated. From the spectrum of FT-IR, it is confirmed that the absorption peak in wavenumbers $3400{\sim}3450[cm^{-1}]$ is small or disappears when BTA is added. AC breakdown strength and volume resistivity of each specimen are investigated. It is considered that the effective content of BTA is about 10[ppm] for the suppression of electrification in this experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.211-215
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• 1996

In this paper, the volume resistivity of transformer oil is made researches so that the electrical properties for transformer oil is investigated. The specimen is produced by the irradiation of electron beam classified into the low dose, such as 0.5[Mrad], 1[Mrad], 2[Mrad]. The effect of electron team irradiation is studied by investigating the electrical properties of dielectric liquid due to the difference of electron beam dose. To measure the physical properties of transformer oil, courier Transform-Infrared Spectroscopy is investigated. And the study far the electrical properties is made by measuring the volume resistivity of each specimen. By means of the result from this experiments, it is introduced that the movement of carrier to contribute to the volume resistivity on the electrical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.55-58
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• 2002

In this paper, the volume resistivity properties of silicone rubber investigated due to temperature dependence. And the measurement of volume resistivity is measured from 1, 5 and 10 minutes when the each applied voltage, for example, DC 100[V], 250[V], 500[V] and 1000[V], is applied. according to the step voltage application method. As a result, The volume resistivity is higher high voltage than low voltage at the room temperature, but is higher low voltage than high voltage at high temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.552-555
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• 1999

In this paper, the volume resistivity properties due to mixture ration of linear low density polyethylene(LLDPE) and ethylene vinyl acetate(EVA) are studied. Electrodes is composed of upper electrode 37(mm $\Phi$), guardring electrode(inner 55(mm $\Phi$ ), and lower electrode 87(mm $\Phi$ In order to measure the leakage current, We used electrometer and stable oven with temperature controller. Measurement method is to measure the leakage current of next specimen after applying the voltage according to 'Step Apply Methods' for ten minutes. In order to measure the volume resistivity properties, the micro electrometer is used, the range of temperature and applying voltage are 25 to 100[$^{\circ}C$] to 100[V] respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.290-293
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• 1997

In this paper, volume resistivity is studied so that the electrical properties for transformer oil due to the stirring temperature of BTA is investigated. A measurement of volume resistivity using the VMG-1000 highmegohm meter is recorded after 10 minutes when the each voltage, and DC 100[V], 250[V], 500[V] and 1000[V] is applied, according to the step voltage appliaction method. A coaxial cylindrical liquid electrode to measure volume resistivity of specimen is used, and its geometric capacitance is 16[pF].