• 제목/요약/키워드: R-Bar

검색결과 645건 처리시간 0.029초

In situ 법에 의한 Cu-Nb3Sn 복합재료선재의 초전도특성과 이에 미치는 Ti의 영향(I) (Superconducting Properties of in situ Formed Multifilamentary Cu - Nb3Sn Composites and the Effects of Ti Addition on the Superconducting Properties (I))

  • 박현순;서수정;이은덕;안재민
    • 열처리공학회지
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    • 제6권1호
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    • pp.17-25
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    • 1993
  • The Cu - $Nb_3Sn$ composites wire as a superconducting material was prepared by in situ method as follow: Cu - 15wt.% Nb alloys which were melted in a high -frequency induction furnace and casted in bar were cold-worked up to the final diameter of 0.24 mm, electroplated with Sn, pre-treated in two steps and then diffused at $550{\sim}650^{\circ}C$ for 24 ~ 96 hrs. The overall $J_c$ and $T_c$ of the specimens were measured by the four point-probe method at 10 K in the magnetic field of 0 Tesla. The overall $J_c$ of the composites wire which diffused at $550^{\circ}C$ after pre-treating in two steps were generally higher than those of the wire at either $600^{\circ}C$ or $650^{\circ}C$. For the specimens diffused at $550^{\circ}C$, the overall $J_c$ were increased until 72 hrs. of diffusion time and then decreased. However, in case of diffusion at $600^{\circ}C$ and $650^{\circ}C$, the overall $J_c$ were gradually decreased from the beginning. The maximum overall $J_c$ obtained in this experiment was $1.3{\times}10^4\;A/cm^2$, which was measured for the specimen diffused at $550^{\circ}C$ for 72 hrs. When the specimens were diffused at $550^{\circ}C$ for 72 hrs, after pre-treating, the measured critical temperature, $T_c$ was 16.19 K. Similar $T_c$ value were obtained in other specimens regardless of diffusion time and temperature.

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Reynolds수 ${10}^{4}$일때 천이영역에서의 왼형제트의 Large-Scale 구조에 관한 연구 (Large-scale structure of circular jet in transitional region at reynolds number of ${10}^{4}$)

  • 이택식;최은수
    • 대한기계학회논문집
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    • 제10권6호
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    • pp.823-829
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    • 1986
  • 본 연구에서는 와동의 대류속도를 H.H. Brunn의 방법과 달리 측정하였으며, 또 이를 이용하여 와동의 중심들 사이의 간격을 구하고자 한다. 이를 위하여 먼저 포텐셜코어영역(potential core region)과 혼합층영역(mixing layer region)의 경계 및 천이영역(transition region)과 난류영역(turbulent region)경계를 구하여야 한다. 각 영역들의 대체적인 구분은 Fig.1과 같다.

Observations of Solar Filaments with Fast Imaging Solar Spectrograph of the 1.6 meter New Solar Telescope at Big Bear Solar Observatory

  • Song, Dong-Uk;Park, Hyung-Min;Chae, Jong-Chul;Yang, Hee-Su;Park, Young-Deuk;Nah, Ja-Kyoung;Cho, Kyung-Suk;Jang, Bi-Ho;Ahn, Kwang-Su;Cao, Wenda;Goode, Philip R.
    • 천문학회보
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    • 제36권2호
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    • pp.88.2-88.2
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    • 2011
  • Fast Imaging Solar Spectrograph (FISS) is an instrument developed by Seoul National University and Korea Astronomy and Space Science Institute and installed at the 1.6 meter New Solar Telescope of Big Bear Solar Observatory. Using this instrument, we observed solar filaments and analyzed the data focusing on determining the temperature and non-thermal velocity. We inferred the Doppler absorption widths of $H{\alpha}$ and Ca II 8542$\bar{A}$ lines from the line profiles using the cloud model. From these values, we separately determined temperature and non-thermal velocity. Our first result came from a solar filament observed on 2010 July 29th. Temperature inside a small selected region of this ranges from 4500K to 12000K and non-thermal velocity, from 3.5km/s to 7km/s. We also found temperature varied a lot with time. For example temperature at a fixed point varied from 8000K to 18000K for 40 minutes, displaying an oscillating pattern with a period of about 8 minutes and amplitude of about 2000K. We will also present new results from filaments observed in 2011 summer.

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회귀분석을 이용한 C소각장에 반입되는 도시고형폐기물의 저위발열량 예측 (Estimation of Lower Heating Value (LHV) of Municipal Solid Waste (MSW) Being Brought into C Incinerator Using Multiple Regression Analysis)

  • 김은영;서정윤
    • 대한환경공학회지
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    • 제35권8호
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    • pp.540-546
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    • 2013
  • 이 연구에서는 C소각장에 반입되는 도시고형폐기물의 저위발열량을 추정할 수 있는 다중회귀직선식을 도시고형폐기물의 습량기준 물리적 조성 성분들로부터 유도하였다. 다중회귀직선식은 LHV = 1,670 + 39.20 Pl + 11.19 Pa - 11.27 Fo이었다. 여기서 LHV: 저위 발열량(kcal/kg), Pl: 습량기준 폐플라스틱류(wt %), Pa: 습량기준 폐종이류(wt %), Fo: 습량기준 음식물류(wt %)이다. 유도된 식의 수정결정계수($\bar{R}^2$)는 0.7476이었고, 이 식에 의한 추정 저위발열량과 측정 저위발열량의 절대백분율오차 평균은 2.42%로 아주 작았다. 그러므로 이 연구에서 유도된 식의 정확성이 높다는 것을 의미한다. 그리고 유도된 식으로 다른 4개 소각장에 반입되는 도시고형폐기물들에 대하여 추정 저위발열량과 측정 저위발열량의 절대백분율오차 평균은 수용할 수 있는 범위(4.74~20.11%)이었다. 더욱이 이 방법은 습량기준 도시고형폐기물의 물리적 조성 성분별로 분류하여 각 조성 성분들의 습량기준 중량 비율만 분석하면 도시고형폐기물의 저위발열량을 추정할 수 있어 보다 경제적이고 또한 대단히 효율적이다.

승강장 혼잡관리를 위한 열차의 정차시간 예측모형 (Development of the Train Dwell Time Model : Metering Strategy to Control Passenger Flows in the Congested Platform)

  • 김현;이선하;임국현
    • 한국ITS학회 논문지
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    • 제16권3호
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    • pp.15-27
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    • 2017
  • 열차 정차시간 증가는 열차 서비스 빈도를 감소시켜 열차와 승강장의 혼잡이 발생하게 된다. 그러므로 열차 정차시간(Train dwell time)에 관한 연구는 열차 운행 계획수립 관점에서 매우 중요하게 다루어 왔다. 본 논문은 계획된 정차시간을 준수할 수 있도록 승객의 유입을 관리하여 승강장 혼잡을 줄일 수 있는 전략들에 활용할 수 있는 실시간 열차 정차시간 예측모형을 개발하였다. 모형의 특징은 실시간으로 수집 가능한 승차인원, 하차인원, 그리고 열차의 중량 등 3가지 독립변수를 적용하였고, 모형의 설명력(${\bar{R^2}}=0.809$)이 대체적으로 정확한 결과를 보여주었다. 실시간 정차시간 모형은 열차가 계획된 정차시간을 준수하도록 승차 승객 수를 조정하는 게이트 미터링 전략에 활용될 수 있다.

미국의 재판외 분쟁해결제도 (A Study on the Alternative Dispute Resolution in America)

  • 김태한
    • 한국중재학회지:중재연구
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    • 제13권2호
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    • pp.181-209
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    • 2004
  • This Study is divided into 5 separate Parts and an Abstract. Part Ⅰ, Ⅱ consist mostly of a collection of problems, current status, motives and the future of ADR. In Pert Ⅲ was described ADR as policies of judicial settlements. We must accept that a diversity of legal culture will always continue to exist. Accordingly we must learn to accommodate those differences of 'culture' around us and to harmonize conflicting laws. This recognition of our reality should in no way be confused with pessimism. In fact if one accepts this perspective of the world ,the study of law seems enriched and becomes academically more challenging. Recently, in the United States, interest in alternative settlement mechanism has increased greatly, which leads me to wonder why such a phenomenon has taken place. In the first place, I'm amazed at the extent to which conciliation or mediation-or the new word, I guess, is alternative dispute resolution, which by now has its own acronym, "A.D.R,"-have gained attention here recently. When 35 years ago, there was virtually no interest in conciliation in this country at the time. What interest there was, was no in the law schools. But looking at the situation now, we have a spate of publications on the subject; we have organizations that are established for no other reason than to promote alternative dispute settlement. We have courses in the law schools. The American Association of Law Schools and the American Bar Association also have active programs. So we have to ask ourselves why. The difference between now and 35 years are striking. On the other hand, I think the interest of the public in ADR has probably been greatly enhanced by the politics of the so-called "poverty programs." I think that many of these assistance programs for the poor-and I do think the "poor" have become a rather expansive political movement beyond simply taking care of the most marginal people of society-have generated money to explore this kind of dispute resolution.

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최적성이론과 독일어 통사론 - 그 가능성과 인지과학적 의의 - (Optimalitatstheoretische Ansatze zur Syntax des Deutschen - Moglichkeiten und kognitionswissenschaftliche Bedeutung -)

  • 남유선;최명원;홍우평
    • 한국독어학회지:독어학
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    • 제8집
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    • pp.89-121
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    • 2003
  • Das Ziel der vorliegenden Arbeit ist zweierlei: Einerseits soll in Anlehnung an Gereon $M\"{u}ller(M\"{u}ller{\;}2000a,{\;}u.a)$ demonstriert werden, dass sich die $Optimalit\"{a}tstheorie$ (OT im folgenden) als eine neue Alternative $f\"{u}r$ syntaktische Beschreibungen des Deutschen auffassen $la\'{u}{\ss}t$; andererseits wird unter dem Gesichtspunk der Kognitionswissenschaft die $Plausibilit\"{a}t$ der OT als eine Theorie der menschlichen Kognition kritisch $\"{u}berpr\"{u}ft$. Diskussionen bzgl. der ersteren Zielsetzung deuten darauf hin, dass syntaktische Eigenschaften des Deutschen im Grunde durch $Kalkulationsvorg\"{a}nge$ $erfa{\ss}bar$ sind, bei denen unter mehreren miteinander konkurrierenden Kandidaten einer als optimal charakterisiert wird. Dabei spielen geordnete und im Prinzip verletzbare $Beschr\"{a}nkungen$ eine zentrale Rolle. Die $Beschr\"{a}nkungsordnung$ bestimmt, welcher Kandidat optimal sein sallte: ein Kandidat, der relativ niedriger eingestufte (oder ggf. gar keine) $Beschr\"{a}nkungen$ verletzt, $schl\"{a}gt$ alle anderen, die relativ $h\"{o}her$ eingestufte (oder ggf. eine einzige) verletzen. Der Gewinner wird dann als optimal und somit als wohlgeformt bezeichnet. Was die zweite Fragestellung anbetrifft, liegt es nahe, dass zentrale Annahrnen der OT im wesentlichen mit denen des Konnektionismus zu vereinbaren sind. Dies besonders in dem Sinne, dass beiden Ansatzen der Empirismus, das Konzept des Wettbewerbs und der $Flexibilit\"{a}t$(Verletzbarkeit, Interaktionen usw.) zugrundeliegen. Ist man also der Ansicht, dass eine neurologisch fundierte Sprachtheorie einer anderen vorzuziehen ist, die neurologische Grundlagen der Sprach nicht mit­$ber\"{u}cksichtigt$, so sollte man u. E. jeden OT -basierten Ansatz emsthaft in Betracht ziehen: Konnektionismus stellt sich $n\"{a}mlich$ die Aufgabe, eine Theorie der Informationsverarbeitung zu erzielen, die gerade die Art und Weise der Informations­verarbeitung des menschlichen Gehims simmuliert.

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Nano Capsulization of Ceramide and the Efficacy of Atopy Skin

  • Zhoh, Choon-Koo;Han, Chang-Giu;Hong, Se-Heum;Kim, In-Young;Lee, Hee-Seob
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.268-279
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    • 2003
  • The nano capsulation of the ceramide was a technique that capsulated ceramide III and tocopheryl linoleate at the mono-vesicle, so as to act the horny layer in skin. It was used 0.5-5.0 wt% of hydrogenated lecithin and 0.01~2.00 wt% of lysolecithin as the membrane-strengthen agents of the mono-vesicle, 5.0~10 wt% of propylene glycol and 5.0~10.0 wt% of ethyl alcohol made by high-pressure Microfluidizer. To enhance the moisturizing efficacy and treat an atopy skin, used ceramide III and tocopheryl linoleate as the active ingredients, and it was made the nano-capsule that synthetic emulsifiers were free. The optimal condition of capsulation of nano ceramide was as follows. The conditions were 3 times at 1,000bar and 60-7$0^{\circ}C$. The particle size showed 63.1$\pm$7.34 nm such as the transparence water as the results for measuring by the laser light scattering. A zeta potential value was -55.1$\pm$0.84 ㎷. The result of the clinical test, the moisturizing effect (in-vivo, n=8, p-value<0.05) was improved 21.15% compared to control, as well as it was improved 36.31 % before the treatment. Moreover, the effectiveness of atopy skin indicated positive reaction that patients were 10 volunteers.

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Expression of Arabidopsis thaliana SIK (Stress Inducible Kinase) Gene in a Potato Cultivar (Solanum tuberosum L. 'Taedong Valley')

  • Yoon Jung-Ha;Fang Yi-Lan;Park Eung-Jun;Kim Hye-Jin;Na Yun-Jeong;Lee Dong-Hee;Yang Deok-Chun;Lim Hak-Tae
    • Plant Resources
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    • 제8권3호
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    • pp.202-208
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    • 2005
  • Osmotic stress is one of major limiting factors in crop production. In particular, seasonal drought often causes the secondary disease in the field, resulting in severe reduction in both quality and productivity. Recent efforts have revealed that many genes encoding protein kinases play important roles in osmotic stress signal transduction pathways. Previously, the AtSIK (Arabidopsis thaliana Stress Inducible Kinase) mutants have shown to enhance tolerance to abiotic stresses, accompanying with higher expression of abiotic stress-related genes than did the wild-type plants. In this study, we have transformed potato (cv. Taedong Valley) with the AtSIK expression cassette. Both PCR and RT-PCR using AtSIK-specific primers showed stable integration and expression of the AtSIK gene in individual transgenic lines, respectively. Foliar application of herbicide ($Basta^{(R)}$) at commercial application rate (0.3% (v/v)) revealed another evidence of stable gene introduction of T-DNA which includes the bar gene for herbicide resistance. Overexpression of the AtSIK gene under dual CaMV35S promoter increased sensitivity to salt stress (300 mM NaCl), which was demonstrated by the reduction rate of chlorophyll contents in leaves of transgenic potato lines. These results suggest that possible increase of osmotic tolerance in potato plants may be achieved by antisense expression of AtSIK gene.

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Equimolar Carbon Dioxide Absorption by Ether Functionalized Imidazolium Ionic Liquids

  • Sharma, Pankaj;Park, Sang-Do;Park, Ki-Tae;Jeong, Soon-Kwan;Nam, Sung-Chan;Baek, Il-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제33권7호
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    • pp.2325-2332
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    • 2012
  • A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.