• 제목/요약/키워드: MAG3

검색결과 226건 처리시간 0.022초

PHOTOMETRIC PROPERTIES OF THE BRIGHT LENTICULAR GALAXY NGC 5102

  • Sohn, Young-Jong;Chun, Mun-Suk;Byun, Yong-Ik
    • 천문학회지
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    • 제24권2호
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    • pp.151-159
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    • 1991
  • Using the photographic imagery of the SO galaxy NGC 5102, the equivalent luminosity profile and the fractional integrated luminosity curve have been derived. Several photometric parameters of the galaxy, such as a total magnitude ($B_T$), equivalent radius ($r^*_e$), effective surface brightness (${\mu}^*_e$), and concentration indices ($C_{21}$, $C_{32}$) were derived from the luminosity profiles. According to the decomposition method from the nonlinear least squares fitting, photometric parameters of the bulge (${\mu}_e$, $r_e$) and the exponential disk (${\mu}(0)$, ${\alpha}^{-1}$), and the bulge to total luminosity ratio (B/T) were obtained. The derived central disk surface brightness (${\mu} (0)\;=\;22.06\;{\pm}\;0.18\;mag/\Box"$) and the evaluated B/T ratio (= 0.52) of the NGC 5102 are close to the mean values (${\mu} (0)\;=\;21.65\;{\pm}\;0.3\;mag/\Box"$, B/T=0.63) of the SO galaxies. Analysis showed that a lens-like hump is embedded in the equivalent luminosity profile of the NGC 5102.

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서양삼 추출물의 초단파 및 식초 처리에 의한 인삼 사포닌 성분 변화 (The Change of Ginsenoside Composition in American Ginseng (Panax quinquefolium) Extract by the Microwave and Vinegar Process)

  • 조희경;곽현희;임병옥;조순현;고성권
    • 생약학회지
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    • 제45권2호
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    • pp.107-112
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    • 2014
  • The purpose of this study is to develop a new preparation process of American ginseng (Panax quinquefolium) extract featuring high concentration of ginsenoside $Rg_3$, $Rg_5$, and $Rk_1$, Red ginseng special components. Chemical transformation from ginseng saponin glycosides to prosapogenin was analyzed by the HPLC. Extracts of American ginseng were processed under several treatment conditions of microwave and vinegar (about 14% acidity). The results showed that the quantity of ginsenoside $Rg_3$ increased by over 0.9% at the 20 minutes of the pH 2~4 vinegar and microwave American ginseng ethanol extract compared with other process times. The result of MAG-20 indicates that the American ginseng microwave and vinegar-processed American ginseng extracts (about 14% acidity) treated for 20 minutes produced the highest amount of ginsenoside $Rg_3$ (0.969%), $Rg_5$ (1.071%), and $Rk_1$ (0.247%). Besides, MAG-15 indicates that the microwave - and vinegar-processed American ginseng extracts (about 14% acidity) treated for 15 minutes produced the highest amount of ginsenoside $Rg_3$ (0.772%), $Rg_5$ (1.330%), and $Rk_1$ (0.386%). This indicates that American ginseng treated with microwave and vinegar had the quantity of the ginsenoside $Rg_3$ over 32 times the amount of the ginsenoside $Rg_3$ (which was not found in raw and American ginsengs) in the average commercial Red ginseng.

A NEAR-INFRARED STUDY OF THE HIGHLY-OBSCURED ACTIVE STAR-FORMING REGION W51B

  • Kim, Hyo-Sun;Nakajima, Yasushi;Sung, Hwan-Kyung;Moon, Dae-Sik;Koo, Bon-Chul
    • 천문학회지
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    • 제40권1호
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    • pp.17-28
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    • 2007
  • We present wide-field $JHK_s$-band photometric observations of the three compact H II regions G48.9-0.3, G49.0-0.3, and G49.2-0.3 in the active star-forming region W51B. The star clusters inside the three compact H II regions show the excess number of stars in the $J-K_s$ histograms compared with reference fields. While the mean color excess ratio $(E_{J-H}/E_{H-K_s})$ of the three compact H II regions are similar to ${\sim}2.07$, the visual extinctions toward them are somewhat different: ${\sim}17$ mag for G48.9-0.3 and G49.0-0.3; ${\sim}23$ mag for G49.2-0.3. Based on their sizes and brightnesses, we suggest that the age of each compact H II region is ${\leq}2\;Myr$. The inferred total stellar mass, ${\sim}1.4{\times}10^4M_{\odot}$, of W51B makes it one of the most active star forming regions in the Galaxy with the star formation efficiency of ${\sim}10%$.

단일 제대 동맥을 가진 건강한 신생아에서 신장 초음파 검사의 유용성 (Usefulness of Routine Renal Sonography Screening for Healthy Infants with Isolated Single Umbilical Artery)

  • 강주미;송은송;국진화;이형신;김소영;최영륜
    • Clinical and Experimental Pediatrics
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    • 제46권9호
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    • pp.854-857
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    • 2003
  • 목 적 : 단일 제대 동맥을 가진 건강한 신생아의 약 1/3에서 위장관 폐색 및 요로 기형을 동반할 수 있으므로 요로 기형을 발견하기 위해 초음파 검사를 관습적으로 시행하고 있지만 실제초음파 검사상 이상이 발견되는 경우는 드물다. 이에 저자는 단일 제대 동맥을 가진 건강한 신생아에서 신장 초음파 검사의 유용성을 알아보고자 본 연구를 실시하였다. 방 법 : 1995년 1월부터 2002년 7월까지 출생 후 이학적 검사상 단일 제대 동맥이 있는 신생아에서 단일 제대 동맥이면서 증후군의 일부이거나 수술적 치료가 필요한 심각한 질환이 동반된 경우는 제외하고 건강한 신생아 총 30명을 대상으로 하였다. 임상적 배경과 출생 72시간 이후 신장 초음파를 실시하였고, 신장초음파상 이상이 있는 경우 지속적 추적관찰과 더불어 배뇨성 방광요도 조영술 및 technetium-99m-mercaptoacetyl-triglycerine(MAG3) 신스캔 검사를 실시하여 수신증의 크기, 폐쇄의 정도 및 신기능 변화를 분석하였다. 결 과 : 총 30명의 남녀비는 1 : 1이었으며 평균 재태 연령은 $38.0{\pm}2.56$주, 평균 출생 체중은 $2,780{\pm}690g$이었다. 단일 제대동맥을 가진 건강한 신생아 30명 중 신장 초음파상 이상이 발견 된 례는 5명으로 16.7%이었고, 의미 있는 요로 기형은 1명으로 3.3%이었다. 이상이 발견된 5명 중 4명은 경도의 수신증으로 추적 검사상 자연 소실되었고, 1명은 심한 수신증으로 배뇨성 방광 요도 조영술상 역류는 없었고 MAG3 검사상 좌측 신장 기능 저하가 보여 외래 추적 관찰 중이다. 결 론 : 단일 제대 동맥을 가진 건강한 신생아에서 신장 초음파 검사상 발견된 신장 이상은 16.7%로 일반인에서 보이는 신장 이상의 빈도와 큰 차이는 없었고 1명을 제외한 4명(80.0%)에서 자연 소실되었으므로, 비용-이익 면에서 볼 때 단일 제대 동맥을 가진 건강한 신생아에서 관습적으로 신장 초음파 검사를 실시하는 것에 대해 고려해 볼 필요가 있다고 사료된다.

SART용 X-밴드 전력증폭기의 설계와 제작에 관한 연구 (A Study on the Design and Fabrication of X-band Power Amplifier for SART)

  • 김철수;김미숙;최병하
    • 한국항해학회지
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    • 제23권3호
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    • pp.29-34
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    • 1999
  • In this paper, an X-band power amplifier using GaAs FET was designed and fabricated, which is to be used as SART transmitter sweeping at the frequency range of 9.2 GHz~9.5 GHz. The amplifier is consist of two stages using ATF-46101 FET of Hewllett-Packard. Finally, the amplifier using microstrip line matching solution shows that MAG is 23 dB at the center frequency of 9.35 GHz.

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초소형위성 SNIPE(Scale Magnetospheric and Ionospheric Plasma Experiment) 시제인증모델의 발사환경시험 및 분석 (Launch Environment Test for Scale magNetospheric and Ionospheric Plasma Experiment (SNIPE) Engineering Qualification Model)

  • 김민기;김해동;최원섭;김진형;김기덕;김지석;조동현
    • 우주기술과 응용
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    • 제1권3호
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    • pp.319-336
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    • 2021
  • 본문은 과학관측임무 초소형위성인 SNIPE(Scale magNetospheric and Ionospheric Plasma Experiment)의 시제인증모델(EQM)에 대한 발사환경시험 수행 결과 및 이를 통해 얻을 수 있는 신뢰성 있는 초소형위성 개발 방향에 대해 논한다. SNIPE는 우주기상관측을 포함한 다양한 탑재체를 지닌 6U급 초소형위성으로 4기가 편대비행을 하며 임무를 수행한다. 다수의 비행모델 제작 전 시제인증모델을 통해 먼저 설계 및 제작의 유용성을 검증하고자 하였다. 시제인증모델의 발사환경시험은 2019년 1차 시험이 수행되었고, 여기서 발견된 일부 문제점을 교정하여 2021년에 2차 시험을 수행함으로써 모든 문제가 해결되었음을 확인할 수 있었다. 두 차례의 시험에서 특이할 점은 1차 시험의 발사관과 2차 시험의 발사관이 다르다는 점인데, 1차 시험용 발사관과 달리 2차 시험의 발사관은 내부의 초소형위성을 고정하는 기능이 있어서 내부 초소형위성이 실제 받는 구조적 하중이 1차 시험에 비해 훨씬 경감되었다는 점이다. 본 논문은 두 시험의 결과로 나타난 특징을 분석하고, 차후 여타 초소형위성의 구조 설계에 반영할 수 있는 지침들을 제시하였다.

Effects of Low Power Laser on Pain Response and Axonal Regeneration in Rat Models with Sciatic Nerve Crush Injury

  • Lee, Hong-Gyun;Kim, Yong-Eok;Min, Kyung-Ok;Yoo, Young-Dae;Kim, Kyung-Yoon;Kim, Gye-Yeop
    • 국제물리치료학회지
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    • 제3권1호
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    • pp.345-355
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    • 2012
  • This study purposed to examine the effect of low power laser on pain response and axonal regeneration. In order to prepare peripheral nerve injury models, we crushed the sciatic nerve of Sprague-Dawley rats and treated them with low power laser for 21 days. The rats were divided into 4 groups: normal group(n=10); control group(n=10) without any treatment after the induction of sciatic nerve crush injury; experimental group I(n=10) treated with low power laser(0.21$mJ/mm^2$) after the induction of sciatic nerve crush injury; and experimental group II(n=10) treated with low power laser(5.25$mJ/mm^2$) after the induction of sciatic nerve crush injury. We measured spontaneous pain behavior(paw withdrawal latency test) and mechanical allodynia(von Frey filament test) for evaluating pain behavioral response, and measured the sciatic function index for evaluating the functional recovery of peripheral nerve before the induction of sciatic nerve crush injury and on day 1, 7, 14 and 21 after the induction. After the experiment was completed, changes in the H & E stain and toluidine blue stain were examined histopathologically, and changes in MAG(myelin associated glycoprotein) and c-fos were examined immunohistologically. According to the results of this study, when low power laser was applied to rat models with sciatic nerve crush injury for 21 days and the results were examined through pain behavior evaluation and neurobehavioral, histopathological and immunohistological analyses, low power laser was found to affect pain response and axonal regeneration in both experimental group I and experimental group II. Moreover, the effect on pain response and axonal regeneration was more positive in experimental group I to which output 0.21$mJ/mm^2$ was applied than in experimental group II to which 5.25$mJ/mm^2$ was applied.

SEOUL NATIONAL UNIVERSITY 4K×4K CAMERA (SNUCAM) FOR MAIDANAK OBSERVATORY

  • Im, Myung-Shin;Ko, Jong-Wan;Cho, Yun-Seok;Choi, Chang-Su;Jeon, Yi-Seul;Lee, In-Duk;Ibrahimov, Mansur
    • 천문학회지
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    • 제43권3호
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    • pp.75-93
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    • 2010
  • We present the characteristics of the Seoul National University 4k Camera (SNUCAM) and report its performance on the 1.5m telescope at the Maidanak observatory in Uzbekistan. SNUCAM is a CCD camera with a pixel scale of 0.266" in $4096{\times}4096$ format, covering $18.1'{\times}18.1'$ field of view on the 1.5m. The camera is currently equipped with Bessell UBVRI, $H{\alpha}$, SDSS ugriz, and Y-band filters, allowing us to carry out a variety of scientific programs ranging from exoplanet studies to survey of quasars at high redshift. We examine properties of SNUCAM such as the bias level and its temporal variation, the dark current, the readout noise, the gain, the linearity, the fringe patterns, the amplifier bias, and the bad pixels. From our observations, we also constructed the master fringe frames in I-, z-, and Y-band. We outline some of the current scientific programs being carried out with SNUCAM, and demonstrate that SNUCAM on the 1.5m can deliver excellent images that reach to the $5-{\sigma}$ detection limits of R~25.5 mag and z~22.7 mag in 1 hour total integration.

Application of Yonsei-Yale isochrones to Globular Clusters in gri band

  • Lim, Dong-Wook;Han, Sang-Il;Chun, Sang-Hyun;Kim, Myo-Jin;Shon, Young-Jong
    • 천문학회보
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    • 제35권2호
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    • pp.83.1-83.1
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    • 2010
  • Recent observations of Sloan Digital Sky Survey (SDSS) for the ugriz filters have provided the largest and the most homogeneous photometric database. Especially, the ugriz systems have been used in many telescopes, such as SDSS, CFHT, and Gemini, and will be applied next generation large telescopes. In addition, many stellar evolution models, like as PADOVA, BaSTI and DSEP, have introduced theoretical isochrones in ugriz system, to apply the isochrones into the photometry of stars in globular clusters. In this study, we transformed Yonsei-Yale($Y^2$) isochrones to ugriz photometric system and fit the isochrones to the (g-r, r), (g-i, r), and (r-i, r) CMDs of 13 globular clusters (Chun et al. 2009, Clem et al. 2008, An et al. 2008). We found that the derived ages from $Y^2$-isochrones are 1~3Gyr younger and the estimated distance moduli are 0.3mag larger than the values inferred from the other isochrones in r-band. Also, the E(B-V) are 0.02~0.04mag less than those estimated from the other models. The ages of each globular cluster estimated from $Y^2$-isochrones are 12~14Gyr and distance moduli show good agreement with previous studies. From this result, we confirmed the availability of the $Y^2$-isochrones in gri filters. However, it is a problem which will improve that E(B-V) values obtained from $Y^2$-isochrones are too small. Finally, the result of this study is expected to be used research of globular cluster in ugirz photometric system.

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