• Journal of the Mineralogical Society of Korea
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• v.26 no.1
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• pp.19-25
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• 2013

Recent progress in Martian exploration identified hematite as the major candidate for the strong magnetic anomalies observed in Martian lithosphere. In the present study, grain-size dependence of thermoremanent magnetization and low-temperature stability of room-temperature saturation isothermal remanent magnetization (RTSIRM) were monitored using synthetic hematites. For hematite, the antiferromagnetic spin configuration is re-arranged from being perpendicular to the c-axis to be parallel to the c-axis below the Morin transition ($=T_M$). A large fraction of RTSIRM is demagnetized at $T_M$ (= 260 K) during zero-field cooling from 300 K to 10 K. About 37% of the initial RTSIRM is recovered on warming from 10 K to 300 K. Shallow Martian subsurface at 1~2 km depth would experience low-temperature cooling-warming of $T_M$ because average Martian surficial temperature is about 220 K. However in most Martian lithosphere whose temperatures are higher than 260 K, the very stable magnetic memory of hematite could be a contributor to Martian magnetic anomalies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1101-1108
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• 2008

This study was carried out to compare the physiological activities of the extracts from Korean and Chinese Viola mandshurica W. Baker. The water extract from leaves of Chinese V. mandshurica exhibited the highest extraction yields of 30.45 g/100 g and the highest content of total flavonoids as 102.30 mg/g. Also, its ethanol extract showed the best content of polyphenol compounds as 136.16 mg/g. The leaf extract of Korean V. mandshurica produced higher electron donating abilities (EDA) of 92.69% (KLW) and 93.61% (KLE) than the other fractions. The strongest SOD-like activity was shown in the ethanol extract from Korean leaves of 17.28% at the concentration of 1.0 mg/mL. The nitrite scavenging abilities (NSA) of the leaf extracts of V. mandshurica from China were intense over 50% at pH 1.2 and 3.0. In the results of inhibitory rates of xanthine oxidase (XO), both ethanol extracts from Korean and Chinese leaves were higher than the other fractions as 98.67% and 93.80% respectively. Effect of tyrosinase inhibition was the highest in the water extract (45.04%) of Chinese leaves, followed by its ethanol extract (31.36%). The results of EDA, SOD-like activity and XO inhibition of the leaf extracts from Korean V. mandshurica were higher than those of Chinese, on the other hand, determinations on total polyphenol contents, NSA and tyrosinase inhibition were higher in those of Chinese.

• Journal of the Korean Magnetics Society
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• v.14 no.4
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• pp.143-148
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• 2004

Effects of residual flux density M$_{res}$ and number of inspection on the detection voltage and flux density B of the gas pipeline were investigated in MFL inspection, which is widely used for the non-destructive inspection in a gas pipeline. A simulation equipment composed of the magnetizer and iron ring attached on an aluminum disc was constructed instead of a huge gas pipeline facility. With this system. the iron ring could be perfectly demagnetized and signals from the bolt screw stuck on the disc could be clearly detected so that the effects of M$_{res}$S and the inspection number on the detection voltage and B of iron ring were effectively investigated. With increasing the number of inspection, M$_{res}$, B of the iron ring and the detection voltage decreased and then kept at constant values while final M$_{res}$ increased with increasing initial M$_{res}$. If inspection condition were kept unchanged, the detection voltage was proportional to the last M$_{res}$ of the iron ring instead of B. This was probably due to magnetic hysteresis of the iron ring inherited from magnetic domain so that consideration on the magnetic hysteresis was inevitable in the analysis of MFL signal from defects of a gas pipeline. A new inspection scheme using the magnetizer with reversed magnetization in the subsequent inspection was proposed from the result that a high detection voltage could be obtained in the first inspection of gas pipeline with positive M$_{res}$.

• Cross-Cultural Studies
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• v.50
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• pp.283-311
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• 2018

The Russian poet A. C. Pushkin left more than a hundred self-portraits in his lifetime. These self-portraits are the subject of a special research project. Pushkin liked to sketch himself disguised in various shapes in his manuscripts. Besides Pushkin, many authors have portrayed themselves, but in terms of their quantity and fame, it is difficult to find self-portraits that transcended those which are as detailed and revealing as that of Pushkin's. Focusing on this point, this paper first examines the position of the poet's self-portraits in the context of the tradition of the self-portrait, as a painting genre full of romanticism as manifested and revealed in the 19th century. Subsequently, this article explains the meaning of the Pushkin's typical self-portraits in profile, which were mostly drawn in his manuscripts. Finally, in order to explore the philosophical implications contained in this poet's self-portraits, this paper attempts to read poet's self-portrait in comparison with Rembrandt's self-portrait, and Montaigne's Essais as well for a comprehensive comparison of the three entities.

• Journal of the Korean Magnetics Society
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• v.5 no.2
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• pp.115-118
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• 1995

We predict the magnetization curves with strains in thin films. It is possible to predict the magretoelastic ani¬sotropy erergy which generates the changes of the M-H curves in thin films. We show the prediction of M-H curves in case of isotropic films such as polycrystalline am amorphous thin films as well as single crystal cubic films.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.208.1-208
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• 1978

Phenol 성 물질이 함유된 산업폐수의 처리와 phenol을 탄소원으로 하는 균체를 이용할 목적으로 공업폐수의 오이로부터 phenol 자화능이 우수한 효모 균주를 선택하여 이 균의 생육에 미치는 환경요인을 조사하였다. 초발 pH 3.5~4.5에서 $35^{\circ}C$ 경우 자화능이 가장 좋았으며 $HgC1_2$ phenylhydrazin $10^{-3}$M 농도에서 완전히 자화능을 잃었다. 배양기 중의 질소원으로 $KNO_3,$ $(NH_2)_2CO가$ 가장 좋았으며 yeast extract 0.01% 첨가하므로써 가장높은 발육효과를 보았다. Phenol을 연속적으로 90시간까지 5회 feeding하며 계속적인 균체증식과 phenol 소모를 보았으며 한편 본균이 catechol, resorcinol도 자화할 수 있다는 점도 알았다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.237-238
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• 2007

전동기 코어 소재로 사용하는 무방향성 규소강판을 토로이달 형태가 아닌 전동기 적용 모형과 동일한 적층형으로 회전자 코어를 제작하여 초기 및 포화 자화 특성에 대한 고찰을 하였다. 초기자화 특성은 전동기가 처음 기동할 때 토크나 기동전류에 큰 영향을 미친다. 초기 자화 특성을 향상시키면 기동 전류를 줄일 뿐 아니라 전동기의 장기간 수명에도 영향을 미친다. 본 연구에서는 무방향성 규소강판의 가공, 설계, 제작 특성이 초기 기동 특성에 미치는 영향을 간접적으로 조사하기 위하여 초기로 포화 히스테리시스 특성에 대한 고찰을 실시하고 이들 요소가 갖는 여러 가지 가능성을 제시하였다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1249-1251
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• 2005

YBCO CC의 초전도 전력기기 응용에 대한 자화손실 저감을 위한 연구가 진행중이다. 본 논문에서는 임계상태 모델에 기초한 수치해석을 이용하여 슬릿개수의 변화에 따른 YBCO CC의 자화손실 저감 특성을 해석하였다. 수치해석을 위한 YBCO CC의 규격은 두께와 폭이 각각 $2{\mu}m$, 4mm이며 슬릿에 의한 선재분한인 필라멘트는 각각 2,4,8개이다. 또한, 수치해석의 결과는 strip모델의 자화손실식과 비교하였다. 해석 결과, 자기적으로 결합되지 않은 strip모델 해석값과 수치해석값은 차이를 보였으며 필라멘트 개수의 변화에 따라 약 1/n 수준으로 자화손실이 저감됨을 확인하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.339-346
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• 2010

Recently, there have been grave concerns that the anticipated increase in the use of nuclear energy worldwide could result in dissemination of sensitive nuclear technologies. To meet the increase in nuclear energy demand and strengthen the non-proliferation regime simultaneously, the various proposals for 'multilateralization of nuclear fuel cycle' have been widely suggested. Those proposals are expected to have serious impacts on our country, if they has come true. In this paper, therefore, the 12 existing proposals were reviewed and assessed for their potential impacts on our country, in order to help prepare the appropriate measures responding to the international attempt of 'multilateralization of nuclear fuel cycle'.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.412-416
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• 2006

A magnetic field oscillator was designed and made. The oscillator was installed around a water pipe and radiated into water which was provided for vegetables cultivation. The oscillator was made with a helmholtz coil and installed a magnetic field sensor inside. The class E amplifier circuit with frequency variance was also used. Hydroponic and soil cultural methods were used for cultivation of lettuce and chinese cabbage with magnetic field water and without. Vitamin C ingredients in the lettuce and chinese cabbage which were grown with magnetic field water were 2.8 times and 1.2 times higher than without the magnetic water. Moreover, the growth acceleration effect of vegetables was shown in lettuce cultivated with the magnetic field water.