• 제목/요약/키워드: Remnant

검색결과 717건 처리시간 0.021초

POLARIZATION OBSERVATIONS OF BACKGROUND RADIO SOURCES SEEN THROUGH THE SUPERNOVA REMNANT S 147

  • Kim, Kwang-Tae
    • 천문학회지
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    • 제21권2호
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    • pp.133-153
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    • 1988
  • Linear polarization has been measured for fifteen extragalactic radio sources in the field of supernova remnant S 147. These observations were made at 4885, 4835, 1665, 1515, 1465, and 1385 MHz using the Very Large Array, primarily to determine unambiguous Rotation Measures (RM) of the sources. This yields a total of 11 new RM sources. Comparisons of a sample of sources which are seen through S 147 were made with sources located farther away. The result tentatively indicates that the distribution of the rotation measure of the former population is broadened, with more than a 85% level of confidence. This constitutes evidence that there is a SNR contribution to rotation measure in sources seen through the SNR. Limits on this RM contribution are statistically at 30 < | RM | < 70 rad $m^{-2}$ with a 85% statistical level of confidence. These result imply the magnetic field in the rim of S 147 has strength 10 microguass if the electron density is $1\;cm^{-3}$.

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Multiple Sluicing in English

  • Park, Myung-Kwan;Kang, Jung-Min
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.394-404
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    • 2007
  • This paper explores the nature of multiple sluicing in English, which has two or more remnant wh-phrases in clause edge position. At the beginning part of the paper we argue against Nishigauchi's (1998) and Lasnik's (2007) Gapping analysis of multiple sluicing, which says that two remnant wh-phrases each actually occupies the left and right edge of a clause, with the in-between string of words undergoing Gapping. We rather argue that multiple sluicing in English is the same kind as found in Bulgarian and Serbo-Croatian. In other words, multiple sluicing in English is also derived by multiple wh-fronting which otherwise does not apply. We demonstrate that some important properties of the construction noted by Lmultiple sluicing, multiple wh-movement/fronting, sluicing, TP/IP-deletion, asnik (2007) under the Gapping approach to it can be accounted for in a principled way by our proposed analysis.

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잔여 전두피판을 한 단위로 이용한 전두연부조직 결손의 재건: 증례보고 (A Case of Forehead Reconstruction with Remnant Forehead Flap Unit)

  • 이성준;김인규;설철환;김석원
    • Archives of Plastic Surgery
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    • 제32권6호
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    • pp.757-759
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    • 2005
  • Acquired defects involving exposed bone on the forehead is challenging to reconstruct. Skin expansion provides an ideal thin flap for forehead aesthetic unit, but it takes long time and high cost, and many patients are dissatisfied at their figures. Free flap can provide enough tissue immediately, but it takes long time and has the risk of mismatches of color and texture. This report details our experiences with two patients who had soft tissue defect on their forehead that was covered with remnant forehead flap unit. This method uses one-unit-forehead island flap based on supratrochlear and supraorbital vessel. We obtained satisfactory results in terms of aesthetic and functional consideration.

THE ENVIRONMENT OF TYCHO: POSSIBLE INTERACTION WITH A MOLECULAR CLOUD

  • LEE J.-J.;KOO B.-C.;TATEMATSU K.
    • 천문학회지
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    • 제37권4호
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    • pp.223-224
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    • 2004
  • The Tycho supernova remnant (SNR), as one of the few historical SNRs, has been widely studied in various wavebands and previous observations have shown evidence that Tycho is interacting with a dense ambient medium toward the northeast direction, In this paper, we report our high-resolution (16') $^{12}CO$ observation of the remnant using the Nobeyama 45m radio telescope. The Nobeyama data shows that a large molecular cloud surrounds the SNR along the northeastern boundary. We suggest that the Tycho SNR and the molecular cloud are both located in the Perseus arm and that the dense medium interacting with the SNR is possibly the molecular cloud. We also discuss the possible connection between the molecular cloud and the Balmer-dominated optical filaments, and suggest that the preshock gas may be accelerated within the cosmic ray and/or fast neutral precursor.

Global Far-UV Emission-line Images of the Vela Supernova Remnant

  • 김일중;선광일;민경욱
    • 천문학회보
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    • 제36권2호
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    • pp.110.2-110.2
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    • 2011
  • Nishikida et al. (2006) presented the first far-ultraviolet (FUV) em${\lambda}$ission-line images of the Vela supernova remnant (SNR) obtained with FIMS/SPEAR instrument. Those include C III ${\lambda}$977, O VI ${\lambda}{\lambda}$1032, 1038, Si IV+O IV] ${\lambda}{\lambda}$1393, 1403 (un-resolved), C IV ${\lambda}{\lambda}$1548, 1551 emission-line images. As a following work, we re-constructed these emission-line images using the new-version processed FIMS/SPEAR data. Additionally, we made N IV] ${\lambda}$1486, He II ${\lambda}$1640.5, O III] ${\lambda}{\lambda}$1661, 1666 emission-line images. The new-version images cover the whole region of the Vela SNR and show more resolved features than the old-version. We compare these FUV emission-line images with other wavelength (X-ray, optical, etc.) images obtained in previous studies.

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Demagnetization Performance According to Vertical and Horizontal Magnetic Bias Fields

  • Kim, Young-Hak;Kim, Ki-Chan;Shin, Kwang-Ho;Yoon, Kwan-Seob;Yang, Chang-Seob
    • Journal of Magnetics
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    • 제16권4호
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    • pp.453-456
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    • 2011
  • Demagnetization for a tube sample which was made of a galvanized steel sheet was performed by applying a magnetic field with a decrement to remove the remanent magnetization of the material. An orthogonal fluxgate magnetic field sensor was used to measure a magnetic field created from a ferromagnetic material. To evaluate the remanent magnetization, the measured magnetic fields were separated into two magnetic field components by the remnant magnetization and the induced one. The horizontal and the vertical bias fields should be controlled separately during demagnetization to remove the horizontal and the vertical components of the remanent magnetization of the tube sample.

Safety Margin Evaluation of Railway wheel Based on Fracture Scenarios

  • Kwon, Seok Jin;Lee, Dong Hyung;Seo, Jung Won;Kwon, Sung Tae
    • International Journal of Railway
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    • 제5권2호
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    • pp.84-88
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    • 2012
  • Derailment due to wheel failure would cause a tremendous social and economical cost in service operation. It is necessary to evaluate quantitatively the safety with respect to high-speed train. Although the safety of railway wheel has been ensured by an regular inspection, all critical defects cannot be detected in inspection cycles and the wheel has been replaced because a defect quickly become critical for safety. Therefore, it is important to calculate quantitatively the fracture limit and remnant life of damaged railway wheel in wheel-rail system. In present paper, the critical crack size of wheel for high-speed train is simulated based on fracture scenario and the safety of wheel is evaluated.

C IV Emission-line Detection of the Supernova Remnant RCW 114

  • Kim, Il-Joong;Min, Kyoung-Wook;Seon, Kwang-Il;Han, Won-Young;Edelstein, Jerry
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.33.3-33.3
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    • 2009
  • We report the detection of the C IV $\lambda\lambda1548$, 1551 emission line in the region of the RCW 114 nebula using the FIMS/SPEAR data. The observed C IV line intensity indicates that RCW 114 is much closer to us than HD 156385, a Wolf-Rayet star that was thought to be associated with RCW 114 in some of the previous studies. We also found the existence of a small H I bubble centered on HD 156385, with a different LSR velocity range from that of the large H I bubble which was identified previously as related to RCW 114. These findings imply that the RCW 114 nebula is an old supernova remnant which is not associated with the Wolf-Rayet star, HD 156385. Additionally, the global morphology of the C IV and $H{\alpha}$ emissions shows that RCW 114 has evolved in a non-uniform interstellar medium.

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Phosphorus in the Young Supernova Remnant Cassiopeia A

  • Koo, Bon-Chul;Lee, Yong-Hyun;Moon, Dae-Sik;Yoon, Sung-Chul;Raymond, John C.
    • 천문학회보
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    • 제39권1호
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    • pp.59.1-59.1
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    • 2014
  • Phosphorus ($^{31}P$), which is essential for life, is thought to be synthesized in massive stars and dispersed into interstellar space when these stars explode as supernovae (SNe). Here we report on near-infrared spectroscopic observations of the young SN remnant Cassiopeia A, which show that the abundance ratio of phosphorus to the major nucleosynthetic product iron ($^{56}Fe$) in SN material is up to 100 times the average ratio of the Milky Way, confirming that phosphorus is produced in SNe. The observed range is compatible with predictions from SN nucleosynthetic models but not with the scenario in which the chemical elements in the inner SN layers are completely mixed by hydrodynamic instabilities during the explosion.

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정보통신기기용 과도전압 차단장치의 개발에 관한 연구 (A Study on the Development of a Transient Voltage Blocking Device for Info-communication Facilities)

  • 한주순
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권2호
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    • pp.159-167
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    • 1999
  • This paper presents a new transient voltage blocking device(TOBD)which low power and high frequency bandwidth to protect info-communication facilities from transient voltages. Conventional protection devices have some problems such as low frequency bandwidth low ener-gy capacity and high remnant voltage. in order to improve these limitations a hybrid type TOBD which consists of a gas tube avalanche diodes and junction type field effect transistor (JFETs) is developed. The TOBD differs from the conventional protection devices in configuration and JFETs are used as an active non-linear element and a high speed switching diode with low capacitance limited high current. Therefore the avalanche diode with low energy capacity are protected from the high current and the TOBD has a very small input capacitance. From the performance test using combination surge generator which can produce $1.2/50{\mu}m$ 4.2 kV/max, $8/20{\mu}m$ 2.1 kAmax it is confirmed that the proposed TOBD has an excellent protection per-formance in tight clamping voltage and limiting current characteristics.

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