• Title/Summary/Keyword: bulge

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Bar Formation and Evolution in Disk Galaxies with Classical Bulges

  • Seo, Woo-Young;Kim, Woong-Tae
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.37.2-37.2
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    • 2019
  • To study the effects of central mass concentration on the formation and evolution of galactic bars, we run fully self-consistent simulations of Milky Way-sized, isolated galaxies with initial classical bulges. We let the mass of a classical bulge mass less than 20% of the total disk mass, and vary the central concentration of a dark matter halo. We find that both classical bulge and halo concentration delay the bar formation and weaken the bar strength. The presence of a bulge increases the initial rotational velocity near the center and hence the bar pattern speed. Bars in galaxies with a more concentrated halo slowdown relatively rapidly as they lose their angular momentum through interaction with the halo. In some of our models, bars do not experience slowdown at the expense of the decrease in their moment of inertia as the bar evolves, with the resulting pattern speed similar to that of the bar in the Milky Way.

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Bulge Characteristics of 1,000 mL Carton Pak according to the Different Storage Conditions (저장유통 조건에 따른 1,000 mL 카톤팩의 벌지현상)

  • 박종대;정관섭
    • Food Science and Preservation
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    • v.10 no.3
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    • pp.293-296
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    • 2003
  • This study was carried out to obtain physical characteristics of paper board and to measure bulge of 1,000 mL carton pak by different storage conditions. Water holding capacity of paper boards were mean of 5.6~7.0%, stiffness of machine direction(MD) was 243.3~266.7 g/cm and cross direction(CD) was 99.2~109.2 g/cm, respectively. The weight of 1,000 mL carton pak were in the range of 29.17~31.26 g. The bulge of carton paks were 6.33~6.93 mm after 7 days at 6$^{\circ}C$ storage, 7.26~8.56 mm after 7 days at 10$^{\circ}C$ and was 8.66 mm after 7 days at 10$^{\circ}C$ treated with 1 hour heat shock per day, respectively. According to this result, the bulge length of 1,000 mL carton pak was showed increased pattern upon increasing the storage temperature and the order was 6$^{\circ}C$ < l0$^{\circ}C$ < 10$^{\circ}C$+ heat shock. To prevent bulge occurence, it was thought to control storage temperature and humidity of paper board or carton pak and to minimize their shock on cold chain system after filling process.

Discovery of a significant population of CN-enhanced red clump stars in the Milky Way bulge: Implications for the formation of early-type galaxies

  • Lee, Young-Wook;Hong, Seungsoo;Lim, Dongwook
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.43.2-43.2
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    • 2017
  • We report our discovery of a significant population of CN-enhanced red clump stars in the classical bulge component of the Milky Way. Since CN-rich stars trace a population with enhanced Helium, Nitrogen, and Sodium originated in globular clusters (GCs), this is a direct evidence that proto-GCs were the major building blocks in the formation of the classical bulges and early-type galaxies in the hierarchical merging paradigm.

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SPATIAL DISTRIBUTION OF STARS AROUND SIX METAL-POOR GLOBULAR CLUSTERS IN THE GALACTIC BULGE

  • Chang, Cho-Rhong;Kim, Jae-Woo;Matsunaga, Noriyuki;Han, Mihwa;Ko, Jongwan;Chun, Sang-Hyun;Kang, Minhee;Sohn, Young-Jong
    • Journal of The Korean Astronomical Society
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    • v.46 no.6
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    • pp.203-224
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    • 2013
  • Wide-field $JHK_s$ images obtained with the SIRIUS near-infrared camera of the IRSF 1.4m telescope are used to examine the tidal structures of the spatial stellar configuration around six metal-poor ([Fe/H]< -1.0) globular clusters located within 3 kpc from the Galactic center. The radial surface density profiles are obtained from the surface photometry of the cluster images and the star counting for the photometric data. For the star counting, candidates of cluster member stars are selected with an filtering algorithm in color-magnitude diagrams. We find that the six target clusters show tidal overdensity features in the radial surface density profiles. There is a break inside the tidal radius for each cluster, and the profile in the outer overdensity region is characterized by a power law. Two-dimensional density maps of all the clusters show distorted asymmetric stellar configurations in the outer region. In five out of the six target clusters, the overdensity features are likely to be associated with the effects of the Galaxy dynamical interaction and the cluster space motions. The observed tidal configurations of stars suggest that several metal-poor clusters in the Galactic bulge are possibly surviving remnants of mergers to build the old stellar system of the Galactic bulge.

The Immunohistochemical Changes of Skin during Hair Follicle Cycle after Depilation in Mice

  • Kim, Dae-Keun;Lee, Chang-Hyun
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.349-357
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    • 2010
  • We have examined the histological changes of skin during hair follicle growth after depilation in C57BL/6N mice. We first studied on histological changes of number of mast cells and thickness of skin during hair follicle growth periods (telogen, 1 day, 3 day, 5 day, 10 day, 14 day, 17 day and 21 day after depilation) by toluidine blue, Giemsa and H&E staining methods. We second studied immunoreactive density of cytokines and Brdu labeled cells in skin during hair follicle growth periods after depilation in C57BL/6N mice by immunohistochemical methods. The histological changes on skin thickness was increased from telogen to 14 day. The number of mast cells was decreased in 3,5 and 10 day and increased in 14, 17 and 20 day after depilation. Immunoreactive density of cytokines [protein kinase C-${\alpha}$ (PKC-${\alpha}$), c-kit, and vascular endothelial growth factor (VEGF)] in 1, 3, 5, 10, and 14 day after depilation was mildly stained in bulge and cutaneous trunci m., but immunoreactive density of cytokines in 17 and 21 day was heavily stained in epidermis, bulge, outer root sheath (ORS), inner root sheath (IRS) and cutaneous trunci m.. Immunoreactive density of Brdu labeled cells in skin in 1 and 3 day was heavily stained in bulge, epidermis and connective tissue under the cutaneous trunci m.. In all periods, immunoreactive density of Brdu labeled cells in skin was heavily stained in bulge, subcutaneous tissue, cutaneous trunci m, ORS and IRS. These experiments suggest that histological changes related to hair follicle growth elevated mast cell counts, skin thickness and epidermis thickness and heavily stained immunoreactive density of cytokines and Brdu labeled cutaneous trunci m. and connective tissue under the cutaneous trunci m. after depilation in C57BL/6N mice.

The Correction of Lower Palpebral Bulge & Tear trough Groove by Repositioning of Orbicularis Oculi Muscle, Orbital Septum & Orbital Fat (눈둘레근육, 눈확사이막 및 지방재배치에 의한 눈꺼풀자루와 눈물받이고랑의 교정)

  • Jin, Eui Sang;Jung, Jae Hak;Kim, Young Hwan;Sun, Hook
    • Archives of Plastic Surgery
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    • v.32 no.3
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    • pp.304-310
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    • 2005
  • Bulging of the lower eyelid & tear trough groove is regarded as a sign of aging. In the past, the surgical excision of the fat pad has been the mainstray of the management of lower palpebral bag in cosmetic blepharoplasty, Recently, fat pad sliding method has been introduced to make more attractive lower eyelids. We used the fat pad for covering the hollowness of the lower eye lid. And we use redundant fat pad for filling & augmentation of the lower eye lid by reflexion. Redraping of the orbicularis arc, with its accompanying midfacial fat repositioning, anatomically restores the cheek and lower lid to make more youthful contour. By redraping and fixing the orbicularis arc on the medial surface of the orbital rim, it becomes a more attractive midface and may prevent of ectropion. From August, 2002 to July, 2004 in correction of lower palpebral bulge & tear trough groove, these two technique were performed in 42 consecutive individuals (84 lower eyelid) for two-year period. Follow up ranged from 3 to 15 months. (an average of 9 months) Palpebral bulge & tear trough groove were corrected and obtained a youthful midface. Complication was rare. The advantages of these techniques are that: prevent in of secondary palpebral bulge and irregularity of lower eyelid by using of reflexed fat fad; prevent in of ectropion. Thus an attractive midface is obtained by redraping of orbicularis arc.

Effects of Disc Degeneration on Biomechanical Behaviors of the Intevertebral Disc: A Biomechanical Analysis (퇴행성으로 인한 추간판의 생체역학적 거동에 대한 분석)

  • Lee Hyun-Ok;Lee Sung-Jae;Shin Jung-Woog;Shin Tae-Jin
    • The Journal of Korean Physical Therapy
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    • v.12 no.3
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    • pp.455-467
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    • 2000
  • The purpose of this study was to analyse the effects of disc degeneration on the biomechanical behaviors of the intervertebral disc in term of axial displacement, intradiscal pressure. disc bulge at the 1.4-1.5 functional spinal unit(FSU). The degeneration is divided 4 grade by initial intradiscal pressure: normal: 135kPa. mild: 107kPa. moderate: 47kPa, severe: 15kPa, The predicted results were follows: 1. The magnitude of the bulge is found to be maximum at the anterior, minimum at the postero-lateral portion. The bulge of lateral, postero-lateral is found to be maximum in severe grade. followed by moderate. mild, normal grade. 2. Tho displacement was increased with increasing compressive load in all four grades.'rho stiffness of disc was found to be reduced by progressing from normal to severe grade. 3. The intradiscal pressure was increased nearly linearly with increasing compressive load in normal and mild grade. But the increasing rate in moderate and severe grade was showed apparently different from nomal and mild grade. Specially, it was increased very slightly in severe grade. In conclusion, decreased intradiscal pressure resulted in increase of axial displacement and disc bulge with compressive load increasing. these may compromise the nerve root impingement or irritation. Therefore posture and activities must be focus to reduce compressive load applied on the back or disc.

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The effect of strain rate on the instability of sheet metal (변형율속도가 판재의 불안정에 미치는 영향)

  • 백남주;한규택
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.935-943
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    • 1988
  • The forming limit diagram is assessed as a means of estimating the forming characteristics of sheet metal and is usually determined experimentally. The strain rates used in the determination are likely to be low. However, often in practice, the strain rates are much higher, so if forming limit diagram is determined at low rates, it may not be appropriate. This paper reconsiders the forming limit diagram for mild steel and aluminum sheet up to variation in strain rate from 10$^{-2}$ sec to 20/sec where its forming has been carried out under oil pressure using a hydraulic bulge test with circular and elliptical dies. To obtain higher strain rate, an impact bulge test had been employed with the same die sets as those used for a hydraulic bulge test. The results obtained are as follows: (1) As the strain rate increases, the fracture pressure increases and the polar height at fracture decreases. (2) Experiment has shown that, in the positive quadrant of the forming limit diagram, the diagram is lowered with increasing strain rate and the effect of strain rate changes according to strain paths and materials..

RELATION BETWEEN BLACK HOLE MASS AND BULGE LUMINOSITY IN HARD X-RAY SELECTED TYPE 1 AGNS

  • Son, Suyeon;Kim, Minjin;Barth, Aaron J.;Ho, Luis C.
    • Journal of The Korean Astronomical Society
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    • v.55 no.2
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    • pp.37-57
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    • 2022
  • Using I-band images of 35 nearby (z < 0.1) type 1 active galactic nuclei (AGNs) obtained with Hubble Space Telescope, selected from the 70-month Swift-BAT X-ray source catalog, we investigate the photometric properties of the host galaxies. With a careful treatment of the point-spread function (PSF) model and imaging decomposition, we robustly measure the I-band brightness and the effective radius of bulges in our sample. Along with black hole (BH) mass estimates from single-epoch spectroscopic data, we present the relation between BH mass and I-band bulge luminosity (MBH-MI,bul relation) of our sample AGNs. We find that our sample lies offset from the MBH-MI,bul relation of inactive galaxies by 0.4 dex, i.e., at a given bulge luminosity, the BH mass of our sample is systematically smaller than that of inactive galaxies. We also demonstrate that the zero point offset in the MBH-MI,bul relation with respect to inactive galaxies is correlated with the Eddington ratio. Based on the Kormendy relation, we find that the mean surface brightness of ellipticals and classical bulges in our sample is comparable to that of normal galaxies, revealing that bulge brightness is not enhanced in our sample. As a result, we conclude that the deviation in the MBH-MI,bul relation from inactive galaxies is possibly because the scaling factor in the virial BH mass estimator depends on the Eddington ratio.

Spatial Configuration of Stars Around Three Metal-poor Globular Clusters in the Galatic Bulge, NGC 6266, NGC 6273, and NGC 6681 : Surface Density Map and Radial Density Profile

  • Han, Mihwa;Chun, Sang-Hyun;Choudhury, Samyaday;Chiang, Howoo;Lee, Sowon;Sohn, Young-Jong
    • Journal of Astronomy and Space Sciences
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    • v.34 no.2
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    • pp.83-97
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    • 2017
  • We present extra-tidal features of spatial configuration of stars around three metal-poor globular clusters (NGC 6266, NGC 6273, NGC 6681) located in the Galactic bulge. The wide-field photometric data were obtained in BVI bands with the MOSAIC II camera at CTIO 4 m Blanco telescope. The derived color-magnitude diagrams (CMDs) contain stars in a total $71^{\prime}{\times}71^{\prime}$ area including a cluster and its surrounding field outside of the tidal radius of the cluster. Applying statistical filtering technique, we minimized the field star contaminations on the obtained cluster CMDs and extracted the cluster members. On the spatial stellar density maps around the target clusters, we found overdensity features beyond the tidal radii of the clusters. We also found that the radial density profiles of the clusters show departures from the best-fit King model for their outer regions which support the overdensity patterns.