• Title/Summary/Keyword: Li Chan

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Determination of $SiO_2$ and $ZrO_2$ in Zircon Sand by Optical Emission Spectrometer (직독식 방출분광기를 이용한 지르콘사 중의 $SiO_2$$ZrO_2$의 분석)

  • Kim, Young Man;Jeong, Chan Yee;Han, Bong Han;Choi, Beom Suk
    • Analytical Science and Technology
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    • v.6 no.3
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    • pp.275-282
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    • 1993
  • A direct and simultaneous method to determine the $SiO_2$ and $ZrO_2$ in zircon sand of raw mineral and its treated one were studied by optical emission spectrometer using DC arc source. The synthetic standard was prepared by mixing with pure metal oxide, and it was diluted with buffer(graphite) and flux($Li_2B_4O_7$). The mixing ratio of buffer and flux and its dilution ratio to sample was investigated in order to choose the best excitation conditions. The optimum mixing and dilution ratios were 0.22:1 and 40, and the standard deviations of analytical results were 1.9% for $SiO_2$ and 4.7% for $ZrO_2$.

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Electrorefining Characteristics of Uranium by Using a Graphite Cathode (흑연 전극을 이용한 우라늄 전해정련 특성)

  • Kang, Young-Ho;Lee, Jong-Hyeon;Hwang, Sung-Chan;Shim, Joon-Bo;Kim, Eung-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.1
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    • pp.1-7
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    • 2007
  • Electrorefining experiments were successfully carried out in LiCl-KCl eutectic molten salt with a graphite cathode. It was found that the formation of Uranium-Graphite intercalation compound(U-GIC) helped the self-scraping mechanism of the uranium dendrite and the efficiency of the electrorefiner increased due to an elimination of the stripping step. The contaminations of the uranium deposit by rare earth elements was negligible while about 300 ppm of carbon was observed. The carbon contamination is believed to be eliminated by further purification by yttrium reaction. The morphology characteristics of the recovered U deposit was compared to that of steel cathode. These are only qualitative preliminary experimental results, but we believe that further research on this type of activity change the direction of the electrorefining research on spent nuclear fuel.

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Topographic Analysis of Landslides in Umyeonsan (우면산 산사태 발생 지점의 지형분석)

  • Ko, Suk Min;Lee, Seung Woo;Yune, Chan-Young;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.1
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    • pp.55-62
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    • 2014
  • In this study, we investigated the landslides area which occurred in Umyeonsan in 2011 and collected landslide location data. Using this field data with aerial photos and LiDAR data which is obtained before and after disaster event, we analyzed the landslide occurrence frequency per unit area about various topographic characteristics. In case of slope, we compared two kind of slopes which are calculated with Neighborhood algorithm and maximum slope algorithm. Also we used aspect, elevation, profile curvature and planform curvature in topographic analysis of landslide occurrence locations. As a result, the region of which maximum slope is $40^{\circ}-45^{\circ}$ is relatively hazardous in landslide. If the perpendicular surface to the direction of the maximum slope is concave, it is more hazardous than other case.

Kojic Acid Protects C57BL/6 Mice from Gamma-irradiation Induced Damage

  • Wang, Kai;Liu, Chao;Di, Chan-Juan;Ma, Cong;Han, Chun-Guang;Yuan, Mei-Ru;Li, Peng-Fei;Li, Lu;Liu, Yong-Xue
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.291-297
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    • 2014
  • The radioprotective effects of a single administration of kojic acid (KA) against ionizing radiation were evaluated via assessment of 30-day survival and alterations of peripheral blood parameters of adult C57BL/6 male mice. The 30-day survival rate of mice pretreated with KA (75 or 300 mg/kg body weight, KA75 or KA300) subcutaneously 27 h prior to a lethal dose (8 Gy, 153.52 cGy/min) of gamma irradiation was higher than that of mice irradiated alone (40% or 60% vs 0%). It was observed that the white blood cell (WBC) count/the red blood cell (RBC) count, haemoglobin content, haematocrit and platelet count of mice with or without KA pretreatment as exposed to a sub-lethal dose (4 Gy, 148.14 cGy/min) of gamma irradiation decreased maximally at day 4/day 8 post-irradiation. Although the initial WBC values were low in KA300 or WR-2721 (amifostine) groups, they significantly recovered to normal at day 19, whereas in the control group they did not. The results from the cytotoxicity and cell viability assays demonstrated that KA could highly protect Chinese hamster ovary (CHO) cells against ionizing radiation with low toxicity. In summary, KA provides marked radioprotective effects both in vivo and in vitro.

A Study on Meaning of Mado(馬刀) (Terms of Surgery in Korean Medicine) (한의학(韓醫學) 외과(外科) 용어(用語) 마도(馬刀)의 의미에 관한 소고(小考))

  • Gu, Yin-Mo;Park, Chan-Young;Lee, Byung-Woo;Kim, Ki-Wook
    • Journal of Korean Medical classics
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    • v.27 no.2
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    • pp.153-162
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    • 2014
  • Objectives : We can discover 'Madohyeobyeong(馬刀挾癭)' and 'Madohyeobyeong(馬刀挾纓)' in LingShu(靈樞). But the meaning of them are not clear. Especially mean of 'Mado(馬刀)' is thoroughly confused. Someone had regarded 'Mado' as a neck region of human body, someone had regarded 'Mado' as a lump of neck region, the others had regarded that mean of 'Mado' is 'longish'. So we would like to find out clear mean of 'Maso'. Methods : We have found out examples of 'Mado' from ancient books and recent research. We have used books in the field of acupuncture, moxibustion and surgery(YangYiDaQuan(瘍醫大 全), WaiKeDaCheng(外科大成), HuangDiNeiJingLingShu(黃帝內經靈樞), ZhenJiuDaQuan(鍼灸大全), ZhenJiuDaCheng(鍼灸大成), WaiKeLiLi(外科理例), ZhenJiuWenDui(鍼灸問對), WaiKeQuanShengJi (外科 全生集), etc.). Results & Conclusions : Generally part of speech of 'Mado' is adjective. So 'Mado' plays the role of modifying shape of lump and abscess. In some cases, 'Mado' had used as abbreviation of longish shaped skin disease.

Synthesis and Characterization of Novel Light-Emitting Copolymers with Electron-Withdrawing Substituents

  • Jin, Sung-Ho;Koo, Dae-Sung;Hwang, Chan-Koo;Do, Jung-Yun;Kim, Young-Inn;Gal, Yeong-Soon;Lee, Jae-Wook;Hwang, Jin-Taek
    • Macromolecular Research
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    • v.13 no.2
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    • pp.114-119
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    • 2005
  • We synthesized two new series of alternating copolymers, poly[bis(2-(4-phenylenevinylene)-2-cyanoethenyl)-9,9-dihexyl-9H-fluoren-2,7-yl-alt-1,4-phenylene](Polymer-I)and poly[bis(2-(4-phenylenevinylene)-2­cyanoethenyl)-9,9-dihexyl-9H-fluoren-2,7-yl-alt-2,7-(9,9-dihexylfluorene)](Polymer-II), via the Suzuki coupling reaction, for use in light-emitting diodes (LEDs). Defect-free uniformly thin films of these polymers were found to be easily formed on indium-tin oxide (ITO) coated glass substrates. Multi-layer LEDs with ITO/PEDOT/Polymer/ LiF/Al configurations with or without an $Alq_3$ electron transport layer were fabricated with these polymers. The maximum EL emissions of Polymer-I and Polymer-II with an $Alq_3/LiF/Al$ cathode were observed at 516 and 533 nm, respectively. The maximum brightness and external luminance efficiency of the devices fabricated with the EL polymers were found to be $411 cd/m^2$ and 0.16 cd/A, respectively.

Performance analysis for the Characteristics of Double/ Single Effect Hybrid type Absorption Chiller (일중/이중효용 하이브리드 타입 흡수식 냉동기 성능 특성에 관한 수치적 연구)

  • You, Da-Young;Song, Tae-Min;Lee, Jung-Byoung;Kim, Hyung-Jin;Im, Ick-Tae;Moon, Sang-Done;Park, Chan-Woo
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.272-278
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    • 2009
  • The characteristics of hybrid type absorption chiller are studied numerically to use a waste hot water effectively. In the case of the full load, the concentration and temperature of LiBr solution are increase about $11^{\circ}C$, 1.3% respectively at the single effect generator by hot water. As a result, the heat of the high temperature generator are decrease, so the energy can be saved. As the partial load decreased the consumption ratio of fuels are decreased and the reduction ratio of fuels are increased. The variation of COP with the inlet temperature of hot water is higher than that of the flow rate of hot water. The effect of mean temperature difference with solution and hot water of the generator are higher that of flow rate of hot water, it can effect on COP which is sensitive to heat of generator.

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Fabrication of λ/2 Phase Plates for Optical Pickup Using a Proton Exchanged LiNbO$_{3}$ (양자 교환된 리튬나오베이트를 이용한 광 픽업용 λ/2 파장판 제작)

  • Son, Gyeong-Rak;Kim, Gwang-Taek;Kim, Yeong-Jo;Song, Jae-Won;Park, Gyeong-Chan;Kim, Jin-Yong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.4
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    • pp.38-44
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    • 2000
  • In this paper, we have been fabricated λ/2 phase plates lot an optical pick-up using a blue violet laser diode by employing proton exchange and wet etching in LiNbO$_{3}$. Their functions and fabrication processes are described in detail. It is established the optimal fabrication conditions through the experimental results. The device characteristics are measured by the Mach-zender interferometer which is composed of the optical components and 632.8nm He-Ne laser. The measured phase error was +5$^{\circ}$~ -6$^{\circ}$(within 3%). This phase plate could be applied an useful device to improve the resolution and the stability of the optical pick-up which has a blue violet laser diode as an optical source.

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A Study on the Principles of Treatment with Prescriptions in ‘Pi Wei Lun’ (동원(東垣) ${\ll}$비위론(脾胃論)${\gg}$ 수록(收錄) 처방(處方)의 치법(治法)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Lee, Yun-Hee;Hwang, Hui-Jeung;Kim, Sang-Chan;Park, Soon-Dal;Byun, Joon-Seok
    • Herbal Formula Science
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    • v.9 no.1
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    • pp.105-136
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    • 2001
  • Objectives : 'Pi Wei Lun' is the principal medical work of Li Dongyuan's writings, which contains most of his medical theories. There are sixty-three prescriptions in 'Pi Wei Lun', and fifty-two of them were originated from him. This study was planned to present assistance to those who apply Dongyuan's theory clinically. Methods : We investigated those fifty-two prescriptions literary, and studied them from a viewpoint of the principle and method of treatment. Results : Dongyuan's fifty-two prescriptions can be classified into eight groups from the viewpoint of the principles and methods of treatment which are composed of 'tonify the spleen and stomach & elevate the spleen Yang', 'elevate the spleen Yang & expel fire', 'elevate the spleen Yang & relieve dampness', 'promote blood flow to eliminate blood stasis', 'invigorate the spleen', 'replenish Ki & and dispel phlegm', 'purgation with drugs warm in nature', and 'the other' eight methods. Conclusions : From above, we concluded that Dongyuan considered 'the primordial energy of the spleen and stomach' as the most important when making up prescriptions, but, at the same time, he used diverse methods of treatment on the ground of differentiation of syndromes.

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Temperature Coefficient of Dielectric Constant in CaTiO3-A(B′, B″)O3 Microwave Dielectric Ceramics (A=Ca, La, Li, B′=Al, Fe, Mg, B″=Nb, Ta)

  • Kim, Jeong-Seog;Cheon, Chae-Il;Park, Chan-Sik;Byun, Jae-Dong
    • Journal of the Korean Ceramic Society
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    • v.40 no.10
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    • pp.925-930
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    • 2003
  • The dielectric polarizability-related factors contributing to the $\tau$$_{\varepsilon}$ have been analysed in terms of dielectric permittivity $\varepsilon$, Tolerance Factor (TF), and octahedron tilt angles in (1-x)CaTi $O_3$-x[A(B', B″) $O_3$] (A=Ca, La, Li, B'=Al, Fe, Mg, B″=Nb, Ta) and (S $r_{0.2}$C $a_{0.8}$)( $Ti_{1-x}$ Z $r_{x}$) $O_3$. All the compounds have the orthorhombic Pbnm structure except the end members A(B', B″) $O_3$ and the solid solutions of x$\geq$0.8. The additional dipole field effect is suggested as a dominant factor contributing to $\tau$$_{\varepsilon}$ in CaTi $O_3$-based ceramics having relatively large $\varepsilon$, which has not been generally considered in the previous reports dealing with the $\tau$$_{\varepsilon}$. This study has been focussed on delineating the dipole field effect on the $\tau$$_{\varepsilon}$ in comparison to the octahedron tilt effect in CaTi $O_3$-based ceramics.cs..cs.