• Journal of the Korean institute of surface engineering
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• v.27 no.6
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• pp.327-334
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• 1994

This work concerns a research for helicon wave plasma generators with applications to materials pro-cessing. For this end, helicon wave plasma source has been designed, constructed and tested. High density plasma was successfully produced and diagnosed with Langmuir probe. The measured maximum plasma de-nsity in this work was $10^{11}cm{-3}$ with 295 gauss of magnetic field and electron temperature was about 3.5eV. The uniformity of plasma densities in the radial direction was excellent with 160 gauss of magnetic field on the cross section which is 10cm apart from the edge of the exciting coil.

• Progress in Superconductivity
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• v.1 no.2
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• pp.115-119
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• 2000

We designed and constructed a non-destructive evaluation system using an HTS DC SQUID electronic gradiometer. Our DC SQUID electronic gradiometer is composed of two DC SQUID magnetometers. The system included a non-magnetic stainless steel cryostat and a set of coaxial exciting coils, which were used to induce an eddy current in the test piece. We also have calculated the eddy current density produced by an exciting coil in any direction of the testing object. We could compute the eddy current density distribution in 3D. The SQUIDs were computer controlled and the output data from the electronic gradiometer was obtained by using a Labview software.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.143-143
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• 1993

현재 시판되고 있는 정장용 생균 제제에 함유되어있는 정장 균주의 하나인 Bifidobacterium bifidum은 항결핵제 중 rifampicin에 감수성으로 rifampicin과 병용 투여시 본래의 정장 효과를 기대할 수없다. 따라서, rifampicin에 내성인 돌연변이 균주를 얻기 위해 B. bifidum을 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)로 처리하여 rifampicin에 내성인 30 종의 균주를 선별하였고, rifampicin에 대한 Minimal Inhibitory Concentration (MIC)를 측정해 본 결과 내성이 1,000 배 이상 상승하였다. 균주 동정을 위하여 fructose-6-phosphate phosphoketolase test를 실시해 본 결과 Bifidobacterium임이 확인되었다. 이들 내성 균주들의 유기산 생산량을 측정하여 그 생산량이 모균주와 가장 유사한 3 종의 균주를 선발하였다. 이들에 대하여 Escherichia coli 생육 억제능을 시험해 본 결과 E. coil 생육 억제능이 모균주와 유사하였다. 또, rifampicin을 함유한 배지에서 돌연변이 균주를 배양시킨 경우 rifampicin이 안정한 상태로 잔존한 것을 알 수 있었다. 이것으로 보아 돌연변이 균주들은 rifampicin을 분해 또는 변형시키는 효소를 생산하지 않는다고 볼 수 있다. 이상의 결과로 본 연구에서 개발한 돌연변이 균주들, 즉 B. bifidum RFRll, RFR21 그리고 RFR61은 rifampicin에 내성이면서 모균주와 동일한 생화학적 특성을 갖는 정장 균주로 여겨진다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.213-213
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• 2011

DC arc plasmatron is powerful plasma source to apply etching and texturing processing. Even though DC arc plasmatron has many advantages, it is difficult to apply an industry due to the small applied area. To increase an effective processing area, we suggest a DC-RF hybrid plasma system. The DC-RF hybrid plasma system was designed and made. This system consists of a DC arc plasmatron, RF parts, reaction chamber, power feeder, gas control system and vacuum system. To investigate a DC-RF hybrid plasma, we used a Langmuir probe, OES (Optical emission spectroscopy), infrared (IR) light camera. For RF matching, PSIM software was used to simulate a current of an impedance coil. The results of Langmuir probe measurements, we obtain a homogeneous plasma density and electron temperature those are about $1{\times}1010$ #/cm3 and 1~4 eV. The DC-RF hybrid plasma source is applied for plasma etching experimental, and we obtain an etching rate of 10 ${\mu}m$/min. through a 90 mm of reaction chamber diameter.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.813-818
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• 1997

In this study the thin film air core and magnetic core inductors consisting of planar coil and/or CoNbZr amorphous magnetic layers on a Si substrate were fabricated as spiral type by using rf magnetron sputtering and wet etching methods. The etchant solution was achieved by iron chloride solution(17.5 mol%) mixed with HF (20 mol%) during 150 sec which etched Cu films and CoNbZr/Cu/CoNbZr multi-layer films. They were about 10${\mu}{\textrm}{m}$ of thickness and 10$\times$10 mm$^2$of size. The properties of thin film magnetic core inductor were 400 nH of Q value at 10 MHz and the resonance frequency was about 300 MHz.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1414-1416
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• 1997

The electrical breakdown characteristics of the synthetic fluids No.2 of KS class VII used for insulating and cooling the materials for the ignition coil are studied. Also, Benzotriazole(BTA) as the streaming electrification suppressant additive is added to the oil, and the change of 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 are analyzed. The breakdown strength of specimen by adding BTA is higher than virgin specimen in low e region, but lower than that in high region because of melting BTA. It is considered that the effective content of BTA as charge suppressant additive is about 10[ppm] from the results of AC breakdown.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.274-280
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• 1994

담배나방(Heliothis assulta) 혈림프 항세균성 단백질의 특성을 알아보기 위해 종령 유충의 혈강으로 고라구연us thuringiens논 균을 주입하였다. 혈림프의 항세근적 활성은 주입후 48시간 경과군에서 가장 높았으며, E. coli와 풍 thuringiensis에 대하여 항세균성을 보이는 두 개의 단백질(G-1 및 G-11)들을 cation exchange chromatography와 gel filtration을 통해 정제하였다 49KD와 46KB의 두 subunit로 구성된 G-1은 높은 glvcine(17 13 mole %) 및 alanine(13.88 mole %) 함량을 보였으며, 14KD의 단일 pclvpeptide인 G-11에서는 histidine(16 14 mole %)과 glvclne(14.27 mole %)의 함량이 높아, 이러한 높은 glvcine 함량에 있어서 곤충에서 나타나는 다른 항세균성 단백질과 공통점을 보인다.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.20-27
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• 2007

In this paper, finite element modeling was performed for vibration analysis of a rotor system installed in sunroof motor, and analysis process was developed for natural frequency and unbalance response analysis. At the same time, to reduce analysis modeling error caused by the difference between analysis and measured values, finite element model updating was conducted using an optimization algorithm, i.e. hybrid genetic algorithm and simulated annealing (HGASA) method. For this end experimental modal test was carried out and by using the measured frequency response function (FRF), model updating was performed considering both cases where core coil was removed and included. And acceptable result was obtained. Also, dynamic property coefficient of bush bearing which influences vibration response of the rotor system was estimated.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1036-1037
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• 2005

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.179-180
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• 2018

자계 검출 센서는 여러 가지 종류가 있으나 벽면에 흐르는 미소 자계 및 차폐 전선에서 검출이 가능한 구조는 초전도 양자 간섭 소자(SQUID)가 주로 사용되지만 가격 및 물성 재료 특성으로 인하여 특수 용도로 사용되고 있다. 이에 본 연구에서는 전선으로부터 발생되는 저주파 자장을 검출할 수 있고 휴대성 및 가격이 저렴한 구조인 코일형 자계측정기를 개발하기 위해 자기 코어 및 코일 Turn수 변화에 따른 자계 검출 감도를 조사하여 최적의 구조를 설정하였다.