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Broad Wings around Hα and Hβ in the S-type Symbiotic Stars

  • Chang, Seok-Jun;Lee, Hee-Won;Lee, Ho-Gyu
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.86.4-87
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    • 2017
  • Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. Many symbiotic stars are known to exhibit broad wings around Balmer emission line. We show high resolution spectra of S-type symbiotic stars, Z Andromedae and AG Draconis, obtained with the ESPaDOnS and the 3.6 m Canada-France-Hawaii Telescope, in which we find prominent broad wings around Balmer lines. We adopt Monte-Carlo technique to consider two types of wing formation mechanisms, which are Thomson scattering by free electron in H II region and Raman scattering by atomic hydrogen in H I region. We find that Thomson wings of $H{\alpha}$ and $H{\beta}$ have the same widths in the Doppler space due to the cross section independent of wavelength. In contrast, Raman $H{\alpha}$ wings are 3 times broader widths than $H{\beta}$ counterparts, which is attributed to the different cross sections and branching ratios. Our CFHT data show that $H{\alpha}$ wings of Z Andromedae and AG Draconis are broader than $H{\beta}$ wings, lending strong support to the Raman scattering origin of Balmer wings in these objects.

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Flow analysis of Buoyant Jets into Storage Tank through Variable Nozzles (각종 Nozzle을 통하여 저장조내로 유입되는 BUOYANT JETS의 유동해석)

  • Pak, Ee-Tong;Cho, Woon
    • Solar Energy
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    • v.9 no.2
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    • pp.42-50
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    • 1989
  • The Buoyant Jets were analysed experimentally changing flow rate (0.0291/s, 0.0371/s, 0.0451/s), ratio of nozzle tip area to throat area (aspect ratio ${\beta}$=0.4, 1.0, 1.9), and also the temperature difference (${\Delta}T=Ti-T{\infty}$) between the temperature of the inflow water into the storage tank ($1m{\times}1m{\times}3m$) and the mean temperature of the water in the storage tank were changed as $25^{\circ}C,\;35^{\circ}C$ and $45^{\circ}C$. The more aspect ratio decreased, the more the trajectories of Buoyant Jets center-line were decreased and not the more the trajectories of Buoyant Jets centerline were influenced by the increment of the difference of the temperature. The more aspect ratio decreased, the more the half widths and dilution ratio of Buoyant Jets were increased and not the more the half widths and dilution ratio of Buoyant Jets were influenced by the increment of the difference of the temperature. Fr number is the factor that can predict the flow pattern over the whole flow field. And yet for the consideration the near field of Buoyant Jets flow pattern is dominated by magnitude of momentum and buoyancy force.

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Appropriate Dimension of Freeway Lane Marking using Computer Based Laboratory Experiment (컴퓨터 기반 실내실험을 통한 고속도로 차선의 적정 규격)

  • Kang, Min Jeong;Oh, Heung Un
    • International Journal of Highway Engineering
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    • v.17 no.1
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    • pp.99-104
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    • 2015
  • PURPOSES : It is well known that experts determined the current standard dimensions of freeway lane markings. However, rigorous engineering rationale could be insufficient regarding whether or not the standard dimensions account for how visible the markings are to the driver. In this study, we seek to optimize the dimensions of freeway lane markings to improve their visibility to drivers. METHODS : The study was conducted as follows. First, alternative lane marking dimensions were selected which could be installed in a test construction site. Second, a video recording was made while driving on the test construction site. Third, subjects were shown the recorded video and then instructed to indicate their preference from among the various lane markings. Lastly, t-tests were applied to assess the statistical significance of differences in the preferences expressed. RESULTS : According to the t-test results, there was no significant difference in the preferences expressed regarding the lane marking widths. However, with regard to the dimensions of freeway lane marking, which represents line marking lengths, gap lengths, and widths of marking, the subjects expressed a preference for specific dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm. CONCLUSIONS : In considering the dimensions of freeway lane markings and their relation to visibility by the driver, it was found that dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm.

Automated assessment of cracks on concrete surfaces using adaptive digital image processing

  • Liu, Yufei;Cho, Soojin;Spencer, Billie F. Jr;Fan, Jiansheng
    • Smart Structures and Systems
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    • v.14 no.4
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    • pp.719-741
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    • 2014
  • Monitoring surface cracks is important to ensure the health of concrete structures. However, traditional visual inspection to monitor the concrete cracks has disadvantages such as subjective inspection nature, associated time and cost, and possible danger to inspectors. To alter the visual inspection, a complete procedure for automated crack assessment based on adaptive digital image processing has been proposed in this study. Crack objects are extracted from the images using the subtraction with median filter and the local binarization using the Niblack's method. To adaptively. determine the optimal window sizes for the median filter and the Niblack's method without distortion of crack object an optimal filter size index (OFSI) is proposed. From the extracted crack objects using the optimal size of window, the crack objects are decomposed to the crack skeletons and edges, and the crack width is calculated using 4-connected normal line according to the orientation of the local skeleton line. For an image, a crack width nephogram is obtained to have an intuitive view of the crack distribution. The proposed procedure is verified from a test on a concrete reaction wall with various types of cracks. From the crack images with different crack widths and patterns, the widths of cracks in the order of submillimeters are calculated with high accuracy.

POLARIZATION OF THOMSON SCATTERED LINE RADIATION FROM BROAD ABSORPTION LINE OUTFLOWS IN QUASARS

  • Baek, Kyoung-Min;Bang, Jeong-Hoon;Jeon, Yeon-Kyeong;Kang, Suna;Lee, Hee-Won
    • Journal of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.1-7
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    • 2007
  • About 10 percent of quasars are known to exhibit deep broad absorption troughs blueward of prominent permitted emission lines, which are usually attributed to the existence of outflows slightly above he accretion disk around the supermassive black hole. Typical widths up to 0.2c of these absorption roughs indicate the velocity scales in which special relativistic effects may not be negligible. Under he assumption of the ubiquity of the broad absorption line region in quasars, the broad emission line flux will exhibit Thomson scattered components from these fast outflows. In this paper, we provide our Monte Carlo calculation of linear polarization of singly Thomson scattered line radiation with the careful considerations of special relativistic effects. The scattering region is approximated by a collection of rings that are moving outward with speeds ${\upsilon}=c{\beta}<0.2c$ near the equatorial plane, and the scattered line photons are collected according to its direction and wavelength in the observer's rest frame. We find that the significantly extended red tail appears in the scattered radiation. We also find that the linear degree of polarization of singly Thomson scattered line radiation is wavelength-dependent and hat there are significant differences in the linear degree of polarization from that computed from classical physics in the far red tail. We propose that the semi-forbidden broad emission line C III]1909 may be significantly contributed from Thomson scattering because this line has small resonance scattering optical depth in the broad absorption line region, which leads to distinct and significant polarized flux in this broad emission line.

A Study on the Bodice and Sleeve Patterns for Middle-aged Women (중년여성을 위한 기본 원형설계)

  • 정혜락;함옥상
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.1
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    • pp.105-115
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    • 2000
  • This study was intended to find body pattern of middle aged women and make new experimental basic pattern for upper-half of the body for them. This experimental pattern on the idea of body pattern analysis was prepared. For experimental pattern, the prototype basic model was chosen with the best qualified D model from the four meaningful existing patterns. After several steps of correction experimental pattern was made. Comparing with basic D model, the new experimental pattern composed of additional bust girth by 1cm, wider back waist by 0.5cm than front waist and additional armhole by 0.5cm keeping the same size for back and front widths. Making a shoulder line up by 3cm the armhole became deeper accordingly and the room for girth has been transferred to length. Front neck girth became deeper downward but back neck girth risen a little bit. Side line of the bodice formed with inward slope taking from the waist line by 2cm. Instead of dart, modified side line slope was more practical by its function and appearance. Abdominal girth which is lower than waist girth by 8.5cm kept in same size with bust girth. Then abdominal girth became more comfortable. New experimental pattern with changes has been examined in function and appearance. In conclusion, the new experimental basic pattern for the middle-aged women has been proved more practical for both in bodice and sleeve than other existing ones in terms of function and appearance.

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Investigation of Temperature Dependence for CNT Semiconductor in External Magnetic Field (외부 자기장내의 반도체 CNT의 온도의존 조사)

  • Park, Jung-Il;Lee, Haeng-Ki
    • Journal of the Korean Magnetics Society
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    • v.22 no.3
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    • pp.73-78
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    • 2012
  • We calculated the electron spin resonance (ESR) line-profile function. The line-width of single-walled carbon nanotube (SWNT) was studied as a function of the temperature at a frequency of 9.5 GHz in the presence of external electromagnetic radiation. The temperature dependence of the line-widths is obtained with the projection operator method (POM) proposed by Argyres and Sigel. The scattering is little affected in the low-temperature region (T < 200 K). We conclude that the calculation process presented in this method is useful for optical transitions in SWNT.

The Black Hole Mass - Stellar Velocity Dispersion Relation of Narrow-Line Seyfert 1 Galaxies

  • Yoon, Yosep;Woo, Jong-Hak
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.75.1-75.1
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    • 2012
  • Narrow-Line Seyfert 1 galaxies are arguably the most important AGN subclass in investigating the origin of the black hole mass-galaxy stellar velocity dispersion (MBH-${\sigma}$) relation because of their high accretion rates close to the Eddington limit. Currently, it is still under discussion whether NLS1s are off from the local MBH-${\sigma}$ relation. We select a sample of 325 NLS1 at relatively low redshift (z<0.1) from the SDSS DR7 by constraining FWHM of $H{\beta}$ in the range of 800-2,200 km/s. Among them, we measured stellar velocity dispersion of 40 objects which show strong stellar absorption lines, e.g. Mg b triplet(${\sim}5175{\AA}$), Fe($5270{\AA}$). In contrast, the other 285 objects show too weak stellar absorption lines to measure velocity dispersion. Using the sample of 40 objects with stellar velocity dispersion measurements, we investigate whether NLS1s follow the same MBH-${\sigma}$ relation as normal galaxies and broad line AGNs. We also test the reliability of the width of narrow lines as a surrogate of stellar velocity dispersion by comparing directly measured stellar velocity dispersion with ${\sigma}$ inferred from [O III], [N II], [S II] line widths, respectively. We will discuss the connection between AGN activity in NLS1s and galaxy evolution based on these results.

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The magnetic properties of optical Quantum transitions of electron-piezoelectric potential interacting systems in CdS and ZnO

  • Lee, Su Ho
    • Journal of IKEEE
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    • v.22 no.1
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    • pp.61-67
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    • 2018
  • We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in CdS and ZnO. In this study, we investigate electron confinement by square well confinement potential in magnetic field system using quantum transport theory(QTR). In this study, theoretical formulas for numerical analysis are derived using Liouville equation method and Equilibrium Average Projection Scheme (EAPS). In this study, the absorption power, P (B), and the Quantum Transition Line Widths (QTLWS) of the magnetic field in CdS and ZnO can be deduced from the numerical analysis of the theoretical equations, and the optical quantum transition line shape (QTLS) is found to increase. We also found that QTLW, ${\gamma}(B)_{total}$ of CdS < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B<25 Tesla.

Physical Characteristics of Anion(SDE)/Zwitterionic(TDB, ODB) Surfactants in Mixed Micelles (음이온(SED)/양쪽성(TDB, ODB) 계면활성제 혼합미셀의 물리화학적 특성)

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.3
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    • pp.238-245
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    • 2004
  • The interaction between anion and zwitterionic surfactants was investigated by means of surface tension, NMR spectroscopy, and fluorescence studies. These systems are N-tetradecyloxymethyl-N,N-dimethyl betaine ($C_{14}$, TDB), N-octadecyloxymethyl-N,Ndimethyl betaine ($C_{18}$, ODB), and sodium dodecylethoxy sulfate (SDE). These systems show a composition dependency in micellar properties. When the molar fraction of TDB and ODB was about 0.6, the cmc values of these systems showed minima, whereas the solubilized amount of a water insoluble dye, NMR line width showed maxima. These changes comes from the intramolecular complexes formed in the mixed micelles. The complexes are due to the electrostatic interaction of oppositely charged head groups of betaine and sodium dodecylethoxy sulfate. A comparison of betaine and SDE alkyl methylene group line widths to those of n-methyl group indicates that the interior of the micelle in the restricted region is more immobile than the head group.