• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.452-452
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• 2011

Using ab initio calculations, we reveal the origins of the extraordinarily increased electric conductivity of the LaAlO3/SrTiO3 interface. In both of the two (LaAlO3)m/ SrTiO3 heterojunction models (m=3, 5), the oxygen atoms in the cells were displaced toward the n-type interface and the Ti-centered octahedron structure was compressed along the [001] direction by the atomic reconstructions at the (LaAlO3)m/(SrTiO3)4 interfaces. As a result, the 3dxy orbital of the Ti atom was preferentially occupied due to the lowered energy state of the 3dxy orbital, which arises from the crystal field asymmetry. We reason that the extra electrons occupy the 3dxy orbital are accumulated at the interface by the displacement of the oxygen atoms. This accumulation contributes to the conductivity of the n-type interface. In addition, through a comparison of the atomic displacements and charge accumulation amounts between the two thickness models (m=3, 5), the thickness-dependency of the conductivity can be explained.

• 한국기록관리학회지
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• 제15권1호
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• pp.7-28
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• 2015

본 연구는 기록연구사의 정보공개청구 업무과정을 밝히고 이와 관련된 문제점을 살펴보고자 하였다. 이를 위해 11명의 현직 기록연구사들과 직접 심층 면담을 시도하여 담당자의 의견과 고충을 들었다. 이들은 주로 정보공개 처리 현황 관리자로서 역할을 이행하고 있었는데 이로 인해 외부 정보공개청구인과 기관 내 구성인 양자로부터 압력을 받는 상황에 놓이게 되는 경우가 빈번하였다. 또한 행정 소송으로 인한 업무 스트레스도 상당한 것으로 밝혀졌는데, 이러한 정보공개 업무의 스트레스는 주업무인 기록관리 업무 수행에 심각한 영향을 미치는 것으로 드러났다.

• 조명전기설비학회논문지
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• 제22권1호
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• pp.157-164
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• 2008

본 논문에서는 모의 GIS 내부에 도전성 파티클을 놓아둠으로써 전하의 축적과 전계의 집중이 용이하도록 하여 부분방전을 모의하였다. 이때 부분방전 발생과 진전에 따른 방사전자파를 스펙트럼 분석기와 EMI.EMC 측정용 안테나($30{\sim}2000[MHz]$)를 사용하여 측정 분석하였다. 모의 GIS 내부에 도전성 파티클 존재에 따른 부분방전의 검출과 방진전전 과정의 판단을 위한 절연진단의 방법으로써 본 논문에서 제안한 측정 주파수의 대역의 분리와 데이터 측정과 분석법을 이용하면 부분방전의 검출과 방전과정의 판단이 가능함을 확인하였다.

• BMB Reports
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• 제46권3호
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• pp.157-162
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• 2013

Human ${\alpha}$-galactosidase A (GLA) has been used in enzyme replacement therapy for patients with Fabry disease. We expressed recombinant GLA from Chinese hamster ovary cells with very high productivity. When compared to an approved GLA (agalsidase beta), its size and charge were found to be smaller and more neutral. These differences resulted from the lack of terminal sialic acids playing essential roles in the serum half-life and proper tissue targeting. Because a simple sialylation reaction was not enough to increase the sialic acid content, a combined reaction using galactosyltransferase, sialyltransferase, and their sugar substrates at the same time was developed and optimized to reduce the incubation time. The product generated by this reaction had nearly the same size, isoelectric points, and sialic acid content as agalsidase beta. Furthermore, it had better in vivo efficacy to degrade the accumulated globotriaosylceramide in target organs of Fabry mice compared to an unmodified version.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.810-816
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• 2017

A graphite calorimetry system was built and tested under irradiation. The noise level of the temperature measurement system was approximately 0.08 mK (peak to peak). The temperature of the core part rose by approximately 8.6 mK at 800 MU (monitor unit) for 6-MV X-ray beams, and it increased as X-ray energy increased. The temperature rise showed less spread when it was normalized to the accumulated charge, as measured by an external monitoring chamber. The radiation energy absorbed by the core part was determined to have values of $0.798J/{\mu}C$, $0.389J/{\mu}C$, and $0.352J/{\mu}C$ at 6 MV, 10 MV, and 18 MV, respectively. These values were so consistent among repeated runs that their coefficient of variance was less than 0.15%.

• Applied Science and Convergence Technology
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• 제23권5호
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• pp.261-264
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• 2014

$SrTiO_3$ (STO) single crystal irradiated with a 3-MeV proton beam exhibits blue and green mixed luminescence. However, the same proton beam when used to irradiate STO with a very thin layer of deposited Pt does not show any luminescence. This Pt layer prevents any damage which may otherwise be caused by arcing, which stems from the accumulated surface voltage of tens of kV due to the charge induced by secondary electrons on the surface of the insulator during the ion beam irradiation process. Hence, the luminescence of ion-irradiated STO originates from the modification of the STO surface layer caused by arcing rather than from any direct ion beam irradiation effect. STO treated with atmospheric-pressure plasma, a simple and cost-effective method, also exhibits the same type of blue and green mixed luminescence as STO treated with an ion beam, as the plasma also creates a layer of surface damage due to arcing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2022-2024
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• 2005

Electrical double-layer capacitor (EDLC) is an electrochemical energy storage device in which electric charges only accumulated by a pure electrostatic attraction force are stored on the electrolyte-electrode interface in a form of double layer and separated by the electrolyte. The composite was prepared by mixing nanosize $TiO_2$ and activated carbon through a means of ultrasonic vibration in ethanol solution for 30 min in various mass ratios of $AC:TiO_2$ to form activated carbone-semiconducting oxide composites. Either 1.0 M $LiClO_4/EC-DEC$ or $Et_4NBF_4$/EC-DEC was used as the electrolyte. It was found that with modification of $TiO_2$, the specific capacitance of activated carbon measured at $1mA/cm^2$ was increased from 40 to 50 F/g. This method is unique in comparison the conventional method because it uses semiconducting TiO2 other than electrochemically active materials such as $RuO_2$. The increase in specific capacitance could be attributed to the decrease in electric polarization, caused by the introduction of $RuO_2$.

• 조명전기설비학회논문지
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• 제22권5호
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• pp.47-52
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• 2008

본 논문에서는 모의 GIS 내부에 도전성 파티클, 미소돌기, 연면방전을 모의함으로 전하의 축적과 전계의 집중이 용이하도록 하여 부분방전을 모의하였다. 이때 부분방전 발생과 진전에 따른 방사전자파를 스펙트럼 분석기와 EMI EMC 측정용 안테나($30{\sim}2,000[MHz]$)를 사용하여 측정 분석하였다. 이러한 결과를 바탕으로 0.3[GHz]에서 1.7[GHz]대역에서 UHF법을 활용한 절연진단이 가능한 UHF 구형 센서를 설계하였다. 이러한 연구결과는 $SF_6$를 사용하는 실제 GIS 및 전력설비의 UHF 절연진단 시스템에 적용 가능한 UHF 진단센서로 활용할 수 있을 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.509-510
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• 2007

The Breakdown properties of epoxy composites are used for transformers and sensor, which has been studied. As a result, From the measurements of breakdown voltage, the more hardener is increased the stronger breakdown strength at low temperature because the ester of hardener is increased. Breakdown strength at the high temperature is decreased because the temperature at $110^{\circ}C$ is near at $T_g$. When the filler is added, between epoxy and silica is formed interface. Therefore the charge is accumulated in it, and the electric field is concentrated, and breakdown strength is decreased than non-filled specimens. In the case of specimens, the treated with silane, the breakdown strength becomes much higher since this is suggested that silane coupling agent has been improved chemical bonding in the interfaces and has been relaxed the electric filed concentration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.86-89
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• 2004

To estimate a electrical performance of the extra high voltage XLPE cable the discharge properties due to shift of void position were investigated. The ${\phi}-q-n$ properties have been measured at room temperature by rising voltage ratio of 0.5[kV]. An obtained data was stored to personal computer through A/D converter. The period of applied wave form and discharge values were divided into 64 parts and discharge values generated during 10 seconds were accumulated by phases. As a result, it was confirmed that the charge, phase angle and counts of discharge changed due to void position.