• Title/Summary/Keyword: Twining

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The Effect of Additives on Twining in ZnO Varistors

  • Han, Se-Won;Kang, Hyung-Boo
    • The Korean Journal of Ceramics
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    • v.4 no.3
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    • pp.207-212
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    • 1998
  • By comparison of the experimental results in two systems of ZnO varistors, it's appear that Sb2O3 is the indispensable element for twining in ZnO varistors and the Zn7Sb2O12 spinel acts as the nucleus to form twins. Al2O3 is not the origin of twining in ZnO varistor, but it was found that Al2O3 could strengthen the twining and form a deformation twining by ZnAl2O4 dragging and pinning effect. The inhibition ratios of grain and nonuniformity of two systems ZnO varistors increase with the increase of Al2O3 content. The twins affect the inhibition of grain growth, the mechanism could be explained follow as: twins increase the mobility viscosity of ZrO grain and grain boundary, and drag ZrO grain and liquid grain boundary during the sintering, then the grain growth is inhibited and the microstructure becomes more uniform.

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3 Cases of Monozygotic Twin Pregnancy after IVF-ET (체외수정 및 배아이식 후의 일란성 쌍태임신 3례)

  • Choi, Sung-Yun;Jung, Byeong-Jun;Choi, Hyung-Min;Kang, Young-Jae;Lee, Eung-Soo;Song, Hyun-Jin
    • Clinical and Experimental Reproductive Medicine
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    • v.27 no.3
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    • pp.295-300
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    • 2000
  • Objective: To report three cases of monozygotic twinning after IVF-ET transfer. Methods: Private practice in two different assisted reproductive technology clinics. Results: Three intrauterine monozygotic twin pregnancies occurred after IVF-ET. One of them was complicated by cord entanglement, another is progressing normal pregnancy without complication and the other was had a normal pregnancy without complication and delivered twin by cesarean section. Conclusion: The reported prevalence of multiple gestations in IVF-ET is a approximately 30%, and it is only 2.7% to be monozygotic twinning in IVF-ET. We report three cases of monozygotic twining after IVF-ET.

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Fe첨가에 따른 지르코늄의 재결정 현상

  • 김영석;권상철;주기남;안상복;김성수
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.37-40
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    • 1998
  • Fe량을 0 - 0.4 wt.%까지 변화시켜 Zr-Fe 이원계 합금을 진공아크용해로 제조한 후 1050 $^{\circ}C$에서 30분 균질화 처리 및 700 $^{\circ}C$에서의 열간압연, 그리고 2회의 걸친 냉간압연 및 열처리를 통하여 판재로 제조되었다. 중간 열처리 시 열처리 온도 및 시간을 조절하여 최종 냉간가공에 앞서 각 시편의 결정립 크기 및 경도 값이 같도록 조절하였다. 최종 냉간가공 시 냉간가공량을 60%로 동일하게 조절하였고, 최종열처리 시 열처리 온도 및 시간을 300-750 $^{\circ}C$, 5-3000분으로 각각 변화시켰다. 재결정 정도는 미세조직 관찰 및 경도 측정으로 평가되었으며, 석출물의 구조, 분포 및 형상 등도 TEM으로 분석되었다. 0.1 wt.% 정도까지의 Fe 첨가는 Fe를 첨가하지 않은 순수지르코늄에 비하여 지르코늄입자의 빠른 성장을 야기해, 조대한 재결정 지르코늄 입자들이 나타났다. 그러나 Fe 첨가량이 0.1wt.%이상 첨가되면, Zr$_3$Fe 석출물에 의한 입자성장 억제효과로 지르코늄 입자의 크기는 오히려 작아졌다. 결론적으로, Fe의 첨가는 지르코늄의 확산을 가속시켰다는 것을 보여준다. 한편, 750 $^{\circ}C$에서 열처리 시 이차 재결정현상으로 지르코늄 입자가 비정상적으로 매우 커졌으며, 동시에 annealing twining 현상이 관찰되었다. 이러한 annealing twining 현상은, 입자성장속도가 임계치 이상으로 갑자기 커진, Zr$_3$Fe 석출물이 거의 없는 합금에서만 나타났다. 이 결과를 토대로 annealing twining 현상은 입자의 빠른 이동이 필요 조건이라는 결론을 도출하였다. .Ar-4vol.%H$_2$ 분위기보다 H$_2$분위기에서 소결했을 때 밀도가 더 높았다. 그러나, 결정립은 $UO_2$$UO_2$-Li$_2$O의 경우, 수소분위기에서 소결했을 때, (U,Ce)O$_2$와 (U,Ce)O$_2$-Li$_2$O에서는 Ar-4vol.%H$_2$분위기에서 소결했을 때 더욱 성장하였다.설명해 줄 수 있다. 넷째, 불규칙적이며 종잡기 힘들고 단편적인 것으로만 보이던 중간언어도 일정한 체계 속에서 변화한다는 사실을 알 수 있다. 다섯째, 종전의 오류 분석에서는 지나치게 모국어의 영향만 강조하고 다른 요인들에 대해서는 다분히 추상적인 언급으로 끝났지만 이 분석을 통 해서 배경어, 목표어, 특히 중간규칙의 역할이 괄목할 만한 것임을 가시적으로 관찰할 수 있 다. 이와 같은 오류분석 방법은 학습자의 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어

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Anti-inflammatory Effect of Hederagenin Glycoside Isolated from Lonicera japonica

  • Son, Kun-Ho;Chang, Hyun-Wook;Kim, Hyun-Pyo;Kang, Sam-Sik
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.136-137
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    • 2002
  • Lonicera japonica Thunb. is a twining shrub that has been used as an antidote and to treat urinary disorders, fever and headache. It has been known as an anti-inflammatory agent in Korea from ancient times and is used widely for treating upper-respiratory tract infections, diabetes mellitus and rheumatoid arthritis. In the previous research, we isolated several flavonoid derivatives from the EtOAc soluble fraction. (omitted)

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Survey of Twin Pregnancy and Parturition in Dairy Cows ('유우의 쌍태 임신 및 분만에 관한조사')

  • Jo Jin Haeng;Kim Yeong Chan;Song Geun Ho;Kim Deok Hwan
    • Journal of the korean veterinary medical association
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    • v.39 no.11
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    • pp.1020-1028
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    • 2003
  • We analyzed the records that distribution of the twinning rate, sex of calves and complications of other diseases with twin pregnancy from 10,012 dairy cows for 5-year period from 70 dairy farms in Paju and Goyang cities. Twining rate was increased for 5-

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The Characteristics of Textiles excavated in Soochonri Tombs of $5^{th}$ Century Baekjae Period (백제 5세기 수촌리 고분군 직물의 특성)

  • Park, Yoon-Mee;Jeong, Bok-Nam
    • Journal of the Korean Society of Costume
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    • v.58 no.10
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    • pp.164-172
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    • 2008
  • Soochonri tombs are assumed to be of the Baekje Kingdom in the early 5th century. We have examined 12 artifacts and 24 textiles in the four tombs. Along with hemp textiles, silk and embroidery threads were found In the Soochonri tombs. Within the hemp textiles both hemp and ramie were made using s-twist threads and the thread count distribution is calculated to be $8.5{\sim}15.5/cm^2$. Taffeta, one of the silk, can be categorized in to four types. First, the plain woven silk was made with warp and weft of the same thickness. The rates of thread count are also similar. Secondly the warp and weft are of the same thickness but has more spaces between threads. Third, the type of warp and weft is different in thickness, the thicker thread woven in the same direction. Lastly, a textile was woven with spaces the same as the width of the reed mark in every two warps. There were five compound weave found. Among them one was made with non-twisted thread for warp and s-twist thread for weft. One plain braiding with apparent spaces between threads were found. All three of the twining were made with wefts thicker than warps, barely showing the warps as a result. Textiles of the Soochonri tombs are the oldest of the Baekje Kingdom studied by far and therefore important artifacts of the Baekje Kingdom. These textiles are similar to those found in the King Muryeong's Tomb and tombs of Gaya and Shilla.

Implementation of Visual Contents on Mandala's Twining Rite (만다라 결연 의식의 시각 콘텐츠 구현)

  • Kim, Kyungdeok;Kim, Youngduk
    • The Journal of the Korea Contents Association
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    • v.15 no.10
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    • pp.37-45
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    • 2015
  • The importance of cultural contents industry is steadily growing owing to the Korean wave etc. and Buddhist cultural contents is a part of the cultural contents. However, the development of Buddhist cultural contents in many ways has left much to be desired. That is because, it is difficult for the public, who is not Buddhist scholar, to understand and take interest in conventional contents on Buddhist books themselves which are digitalized. Also, most contents researches are discussed on the necessity of contents development and just stay in these subjects, but it is insufficient to study a semantic analysis and visualizing contents on Buddhist books. So, in this paper, we analyse mandala's twinning rite in the Buddhist books and implement visual contents on the rite. The mandala is using toohadeokbul in a special way as the abhisinca rite. We analyse concept of the toohadeokbul and implement its visual contents which visualize ideological logic of Buddhism. The implemented contents are able to provide the public with Buddhist cultural experience of the yard. Additional, by trying to visualize descriptive expressions of Buddhist books, this paper could be a precedent for developing visual contents of unlimited data comprised in Buddhist books.

Effect of Initial Texture on the Twinning Formation of AZ31 Mg Alloy (AZ31 Mg 합금의 쌍정 형성에 미치는 Initial Texture의 영향)

  • Lee, Byoung-Ho;Kim, Yong-Woo;Lee, Chong-Soo
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.114-117
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    • 2007
  • In the present study, the effects of initial texture on the twinning formation of AZ31 Mg rolled sheet was investigated. Uniaxial compression tests were performed on samples cut along the normal direction and rolling direction of rolled AZ31 Mg alloy sheet at various temperatures (RT, 200, 250, 300, 350, $400^{\circ}C$) with the 0.01/s strain rate. Pole figure of rolling planes showed that basal planes of most gain were located parallel to the rolling direction. After compression test, microstructures and stress-strain curves results indicated that active deformation twining occurred only at the specimen cut along the rolling direction. The slip-twin transition with the increase of temperature was also investigated.

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Relation Between the Growth Twin and the Morphology of a Czochralski Silicon Single Crystal (초크랄스키 실리콘 단결정에서 성장 쌍정과 결정 외형의 관계)

  • 박봉모
    • Korean Journal of Crystallography
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    • v.11 no.4
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    • pp.207-211
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    • 2000
  • In a Czochralski silicon single crystal, the relation between the growth twin and the crystal morphology was investigated. The growth twin is nucleated on the {111} facet planes near the growth ridges. When a {111} growth twin is formed in the <100> silicon crystal, the growth ridge where twin is nucleated will continuous through the twin plane. Other two ridges at the 90。 apart will be displaced about 33° and be deformed to facets. The ridge on the opposite side of twin nucleation will disappear by forming a slight hill. Because the growth ridges of silicon is due to the {111} planes, the variation in the growth ridge formation can be predicted clearly by considering the change of the {111} plane traces in the stereographic projection after twining.

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Effect of Initial Texture on the Twinning Formation of AZ31 Mg Alloy (AZ31 Mg 합금의 쌍정 형성에 미치는 초기 집합조직의 영향)

  • Lee, Byoung-Ho;Kim, Yong-Woo;Park, Sung-Hyuk;Lee, Chong-Soo
    • Transactions of Materials Processing
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    • v.16 no.6
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    • pp.467-472
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    • 2007
  • In this study, the effects of initial texture on the twinning formation of AZ31 Mg rolled sheet was investigated. Uniaxial compression tests were carried out on samples cut along the normal direction(ND) and roiling direction(RD), respectively, of rolled AZ31 Mg alloy sheet at various temperatures (RT, 200, 250, 300, 350, $400^{\circ}C$) with the fixed strain rate($10^{-2}/s$). The results showed that deformation twining occurred actively only in the RD specimens, which promoted homogeneous deformation as compared to the ND specimens. The effect of temperature on the formation of deformation twins was also investigated, and the slip/twin transition temperature was found to be approximately $250^{\circ}C$.