• 제목/요약/키워드: R170

검색결과 529건 처리시간 0.023초

Spectroscopic Survey of G and K Type Dwarfs in the Hipparcos Catalog

  • Kim, Bokyoung;An, Deokkeun;Lee, Young Sun;Stauffer, John R.;Terndrup, Donald M.;Johnson, Jennifer
    • 천문학회보
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    • 제40권1호
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    • pp.70.5-71
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    • 2015
  • We present a preliminary result from a high-resolution and high signal-to-noise spectroscopic survey, providing atmospheric parameters for about 170 nearby field dwarfs in the Hipparcos catalog. Our preliminary analysis shows that when Hipparcos parallaxes are adopted, a few stars in our sample are too faint compared to main-sequence fitting distances based on our accurately measured [Fe/H]. We discuss magnitude deficits of these field stars in connection with the short Hipparcos distance to the Pleiades.

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아미노산 Phenylthiohydantoin 유도체를 키랄 고정상으로 한 GC에 의한 아미노산 광학 이성질체의 상호분리 (Separation of Amino Acid Enantiomers by Gas Chromatogaphy on Phenylthiohydantoin Derivatives as Chiral Stationary Phases)

  • 박만기;양정선;고창범;이미영
    • 약학회지
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    • 제32권3호
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    • pp.170-176
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    • 1988
  • The resolution of five amino acids derivatives by gas chromatography on phenylthiohydantoin derivatives as chiral stastionary phase was investigated. (S)-5-isopropyl, isobutyl, (sec)-butyl and benzoyl derivatives of $N^3-phenyl-2-thiohydantoin$ were synthesized from L-valine, L-leucine, L-isoleucine and L-phenylalanine, respectively. The phases were employed at several column temperatures ($140^{\circ}C{\sim}210^{\circ}C$). The separation factors were compared with each stationary phase with varying R groups. The possible mechanism of chiral recognition was investigated by NMR technique.

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점탄성층이 부분적으로 삽입된 샌드위치보의 횡진동 특성 (Behavior of the Flexural Vibration of a Sandwich Beam with Partially Inserted Viscoelastic Layer)

  • 박진택;최낙삼
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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    • pp.167-170
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    • 2000
  • The flexural vibration of a sandwich beam with partially inserted viscoelastic layer has been studied using the finite element analysis in combination with an experiment. Effects of length and thickness of partial viscoelastic layers on system loss factor(${\eta}_s$) and resonant frequency(${\omega}_r$) were considerably large. The thicker the viscoelastic layer in a sandwich beam, the larger the system loss factor in Mode 1 as compared with that in Mode 2. The loss factor increased almost linearly with increasing the length of partial viscoelastic layer. Effects of thickness of beams were also considered.

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유전자 재조합에 의해 제조된 하루딘의 항응고 작용 (Evaluation of Anticoagulant Activity of Recombinant Hirudin)

  • 김영식;엄은미;정정숙;정춘식;정기화;손정훈;최의성;이상기
    • Biomolecules & Therapeutics
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    • 제1권2호
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    • pp.166-170
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    • 1993
  • Hirudin is a potent inhibitor of thrombin, which was originally obtained from the medicinal leech (Hirudo medicinalis) Now it is being produced through the recombinant technology on a large scale. Recombinant hirudin has been assayed for the anticoagulant activity by the measurement of clotting time and the inhibition of thrombin actvity using a chromogenic substrate. The assay range of partial thromboplastin time and thrombin time is within $0.2{\sim}1.0 {\mu}g/mι.$ Thrombin time is more sensitive to the measurement of clot. Ex vivo study showed the level of hirudin in rat plasma was highest in 10 min and then it was eliminated slowly. The half-life of r-hirudin was 80~110 min depending on the assay methods. Intraveneous injection of russel viper venom was used for thrombus induction combined with vents cava ligation. Inhibition of venous thrombosis was observed with i.v. hirudin. It was dependent on the concentration of hirudin.

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Bis-(p-bromophenyl)phosphate에 의한 PET 직물의 방염가공 (Flame Retardant Finish of PET fabrics with Bis-(p-bromophenyl) phosphate)

  • 조환;최창호;이광우;조인술;김수창;허만우
    • 한국염색가공학회지
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    • 제2권4호
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    • pp.251-256
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    • 1990
  • Bis-(p-bromopheny)phosphate(BBPP) , which serves as flame retardant for PET fabric, was synthesized from phenol and phosphorus oxychloride, and from bromine. In order to investigate the flame retardancy of BBPP, PET fabrics were steam-cured with diluted BBPP solution. The following conclusions were drawn : 1. Flame retardancy of PET fabrics treated with BBPP was excellent, and optimal treating condition was 10% concentration of flame retardant at $170^{\circ]C$ 2. Clark softness and tensile strength before and after the laundering of PET fabrics treated with flame retardant remained nearly unchanged.

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Al-Zn-Mg 계 합금의 Creep 거동에 관한 연구 (A Study on the Creep Behaviour of Al-Zn-Mg Alloy)

  • 박종건;최재하
    • 열처리공학회지
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    • 제6권2호
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    • pp.79-88
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    • 1993
  • The static creep mechanism and behaviour of Al-Zn-Mg alloy have been investigated under condition of constant stress tension creep test in the temperature and stress range of $170-260^{\circ}C$ and 5-12.5 $kg/mm^2$ respectively. The experimental result are follows : The stress exponent value for creep was observed to about 7.3-6.43 and the activation energy for creep deformation was 44-41 kcal/mol. Larson-Miller parameter P for the crept specimens under the creep condition was obtained as P = (T + 460) (log $t_r$ + 8.6). Emperical equation for the creep rate was obtained by the computer simulation as follows. $${\varepsilon}\;=\;\exp[(-5.519{\times}10^{-4}{\sigma}+2.33{\times}10^{-2})T-6.98{\sigma}+18.295]{\times}{\sigma}^{-0.0142+10.18}\exp[\frac{(-6{\sigma}+47.8)1000}{RT}]$$ Fracture was dominated by intergranular mechanism over the experimental range.

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An Application of the Novel Techniques Detecting Partial Discharge Employable to GIS Using Optical Sensor

  • Ryu, Cheol-Hwi;Jung, Seung-Yong;Koo, Ja-Yoon;Yeon, Man-Seung
    • Journal of Electrical Engineering and Technology
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    • 제2권3호
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    • pp.396-400
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    • 2007
  • A novel technique has been proposed and related experimental works have been performed in order to detect the partial discharges and the location of the possible defects introduced into the Gas Insulated Switchgear. For this purpose, a prototype HY Pockels sensor has been developed and then employed in order to investigate its field applicability for finding the location of the defects using a 170kV GIS mock-up. Our proposed sensor enables us to measure the electric field variation due to the PD occurrence. In addition, the different PD patterns are observed, which might be dependant on the location and the distance of the sensor with respect to the PD source. Throughout this work, its linear response has been proved to be admissible as a function of the applied voltage. And also the position of the PD source might be distinguished by comparing the PD patterns.

디지털 이미지 색채분석을 이용한 재택근무 공간색채배색에 관한 연구 (A Study on the Color Harmony Scheme of the Home Office Based on Digital Color Image Processing)

  • 정현원;이현수
    • 한국실내디자인학회논문집
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    • 제13권3호
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    • pp.162-170
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    • 2004
  • The purpose of this study is to analyze the emotional color of home office and the trendy color with special comparison of office and library colors, and to suggest the harmony of color combination of home office based on the emotional color of this analytical data. this study, the Color Syntax Program, digital tool for color analysis of images is used. The results of this study are as follows. Firstly, the main color of home office images shows three color classifications of YR-Y, Y-GY, R-YR, and with relatively high ratios of YR-Y in the color of home offices, and B-PB, GY-G in offices and libraries. Secondly, from the point of emotional aspect, the trendy color of the home office can be classified into four color image categories: 'natural', 'peaceful', 'mild', and 'noble'. Under those categories this paper proposes 10 color harmony scheme that can be applied to color of home office interior design.

A Distribution Automation System Simulator for Training and Research

  • Gupta R. P.;Srivastava S. C.
    • KIEE International Transactions on Power Engineering
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    • 제5A권2호
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    • pp.159-170
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    • 2005
  • This paper presents the design and development of a scaled down physical model for power Distribution Automation (DA) system simulation. The developed DA system simulator is useful in providing hands-on experience to utility engineers / managers to familiarize with the DA system and gain confidence in managing the power distribution system from the computer aided distribution control center. The distribution automation system simulator can be effectively used to carry out further research work in this area. This also helps the undergraduate and graduate students to understands the power distribution automation technology in the laboratory environment. The developed DA simulator has become an integral part of a distribution automation lab in the Electrical Engineering Department at Indian Institute of Technology Kanpur in India.

Synthesis of Silicon Carbide Nanowhiskers from Coconut Fibres and Sol-Gel Derived Silica

  • Raman, V.;Bhatia, G.;Mishra, A.;Saha, M.;Sengupta, P.R.;Srivastava, A.K.
    • Carbon letters
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    • 제7권3호
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    • pp.166-170
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    • 2006
  • Silicon carbide whiskers ($SiC_w$) having the diameter in the range of 20-80 nm were synthesised from coconut fibres through sol-gel process. The coconut fibres were impregnated with tetraethoxysilane and methyltriethoxysilane derived sol and pyrolyzed at $1400^{\circ}C$ in argon. X-ray of the pyrolyzed samples showed the formation of ${\beta}$-SiC.

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