• 제목/요약/키워드: morphology formation

검색결과 1,213건 처리시간 0.03초

STUDYING THE MORPHOLOGY AND STAR FORMATION OF GALAXIES AS A PROBE OF GALAXY EVOLUTION

  • CHEN, HSUAN-JU;HWANG, CHORNG-YUAN
    • 천문학논총
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    • 제30권2호
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    • pp.511-512
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    • 2015
  • Star formation activities dominate the evolution of galaxies. Elliptical galaxies are believed to be old galaxies in the Hubble sequence, and elliptical galaxies at different evolution epochs might have different star formation activities and/or morphologies. We investigate the connection between star formation rates and the morphology of elliptical galaxies. With the Sloan Digital Sky Survey (SDSS) and the Galaxy Zoo, we select a sample of elliptical galaxies by morphology and consider their infrared emission as an index of star formation rate to study the relation between the star formation rates and their morphological properties, such as ellipticities. In addition, we select some nearby spiral galaxies with very low MIR emission to probe the mechanisms of these red spiral galaxies. We display our preliminary results and discuss their implication on the evolution of galaxies in this poster.

전면 전극 형성 시 표면 형상이 미치는 영향 분석 (Analyzing the Effect of Si Surface Morphology on Front Electrode Formation)

  • 한혜빈;최동진;강동균;박현정;배수현;강윤묵;이해석
    • Current Photovoltaic Research
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    • 제7권4호
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    • pp.130-133
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    • 2019
  • The Ag crystallite formed during the formation of the front electrode forms a contact between the metal of the electrode and the emitter of the cell. Contact between the electrode and emitter plays an important role in collecting electrons generated by the solar cell. Therefore, Ag crystallite formation is an important factor. In order for solar cells to have good characteristics, it is important to understand the factors influencing the Ag crystallite formation. Factors affecting the formation of Ag crystallites include Si emitter, morphology, Si defect and firing temperature. The influence of surface morphology on Ag crystallite formation was confirmed throughout this study. In the case of fine texturing, the Ag crystallites were formed at the pointed parts. The finer the texturing, the sharper areas and more Ag crystallites were formed. This was confirmed by SEM image and FF calculation.

자전 고온 반응 합성법에 의한 AlN 분말의 제조 II, Al 분말로부터 AlN 분말의 형성기구 (Fabrication of AlN Powder by Self-propagating High-temperature Synthesis II. The formation Mechanism of AlN Powder from Al Powder)

  • 안도환;전형조;김석윤;김용석
    • 한국세라믹학회지
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    • 제33권10호
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    • pp.1089-1094
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    • 1996
  • In this study the formation mechanism of AlN synthesized by SHS(Self-propagating high-temperature Syn-thesis) was studied in order to obtain uniform AlN powder size and morphology. Based on the morphology of AlN synthesized and the calculation of the temperature of Al powder as a function AlN layer thickness the formation mechanism of AlN was proposed.

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Electrochemical Studies on the Mechanism of the Fabrication of Ceramic Films by Hydrothermal-Electrochemical Technique

  • Zhibin Wu;Masahiro Yoshimura
    • Bulletin of the Korean Chemical Society
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    • 제20권8호
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    • pp.869-874
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    • 1999
  • In this paper, electrochemical techniques are used to investigate hydrothermal-electrochemically formation of barium titanate (BT) ceramic films. For comparison, the electrochemical behaviors of anodic titanium oxide films formed in alkaline solution were also investigated both at room temperature and in hydrothermal condition at 150.0 ℃. Film structure and morphology were identified by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Titanium oxide films produced at different potentials exhibit different film morphology. The breakdown of titanium oxide films anodic growth on Ti electrode plays an important roles in the formation of BT films. BT films can grow on anodic oxide/metal substrate interface by short-circuit path, and the dissolution-precipitation processes on the ceramic film/solution interface control the film structure and morphology. Based upon the current experimental results and our previous work, extensively schematic proce-dures are proposed to model the mechanism of ceramic film formation by hydrothermal-electrochemical method.

Formation and Related-Behavior of Micro-bowl Morphology Consisting of Ionic Palladium(II) Complexes

  • Kim, Cho-Rong;Kim, Chi-Won;Noh, Tae-Hwan;Lee, Young-A;Hong, Jong-Ki;Jung, Ok-Sang
    • Bulletin of the Korean Chemical Society
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    • 제31권8호
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    • pp.2223-2227
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    • 2010
  • Reaction of [(bpy)Pd]$(PF_6)_2$ (bpy = 2,2'-bipyridine) with racemic bis(isonicotinoyl)-1,1'-bi-2-naphtholate (L) in acetone, and followed by addition of chloroform and solvent evaporation allows to form amorphous micro-bowl morphology consisting of $[(bpy)PdL]_2(PF_6)_4$ without any template or additive. In contrast, the reaction and recrystallization in acetone for 1 week produce parallel-piped single crystals consisting of $[(bpy)_3Pd_3({\mu}_3-HPO_4)_2](PF_6)_2$. The formations of micro-bowl and parallel-piped single crystal morphologies appear to be primarily associated with the kinetic and thermodynamic control, respectively. The formation of micro-bowls may be attributed to eruption of organic solvents. Cosolvent effects and chemical properties on the formation of micro-bowl morphology have been observed.

판상엽 품질 특성 분석 (제1보) - 물리적ㆍ구조적 특성에 관하여 - (Quality analysis of Reconstituted tobacco ( I ) - On the Physical and Structural properties -)

  • 한영림;나도영;김삼곤;김근수;강영희
    • 한국연초학회지
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    • 제26권1호
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    • pp.57-63
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    • 2004
  • A comparative analysis of characteristics of domestic and foreign reconstituted tobacco based on papermaking was conducted to evaluate the quality of reconstituted tobacco and to utilize as basic data for improvement of domestic reconstituted tobacco. In the formation, which is key factor to quality and physical properties of product, foreign reconstituted tobacco has better uniform formation than those of domestic one. These result was attributed to distribution of large floc size in the domestic one unevenly. In the fiber morphology, domestic reconstituted tobacco has larger average fiber length and width than those of foreign one. They indicated that fiber morphology of domestic one will exert structural properties of paper such as formation and permeability. Tensile strength of domestic one has lower than those of foreign one by basis weight. In the air permeability, domestic one was remarkably reduced because base web was over sized. It also will affect the combustibility of reconstituted tobacco. In summary, we conclude that the physical and structural properties of domestic reconstituted tobacco result in quality deviations compared with foreign reconstituted tobacco.

Carbon Containing Compositions

  • Mansurova, R.M.;Mansurov, Z.A.;Soh, Deawha
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.335-338
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    • 2001
  • With the use of the electron microscopy and X-ray phase analysis the regularities of carbon deposit formation in process of methane and propane pyrolysis on the zeolites, Kazakhstan natural clays, chrome and bauxite sludge containing metal oxides of iron subgroup, have been studied. In process of over-carbonization the trivalent iron was reduced to metal form. In addition, the carbon tubes of divers morphology had been impregnated with ultra-dispersed metal particles. The kinetic parameters of carbon formation in process of methane decomposition on the zeolite CoO mixture surface were investigated by method of thermo-gravimetric analysis. The morphology and structure of formed carbon fibrils, with the metal particles fixed at their ends, have been investigated, the formation of branched carbon fibrils pattern, so called octopus, being found.

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H$\alpha$ IMAGING AND PHOTOMETRY OF BLUE COMPACT GALAXIES WITH 6-M TELESCOPE

  • NEIZVESTNY S. I.;KNIAZEV A. YU.;LIPOVETSKY V. A.;PUSTILNIK S. A.;UGRYUMOV A. V.;KORABLINA N. B.;ISAENKO V. N.
    • 천문학회지
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    • 제29권spc1호
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    • pp.77-78
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    • 1996
  • We perfom a large project for complex study of Blue Compact Galaxies (BCGs) with strong star formation, which includes optical spectroscopy, BVR CCD photometry and HI 21 cm radio survey. The most interesting galaxies are studied also with HST and VLA. In the frame of this project we began the study of H$\alpha$ morphology of BCGs with 6-m telescope. We present and discuss here the results for the first 6 galaxies. We found the noticeable variety of forms for H$\alpha$ morphology comparing to broad band images: from very compact HII region in very center of stellar body (Mark 996, possible dwarf post-merger, old galaxy experiencing strong star formation burst), to very extended gas emission encompassing the whole area traced by stars (SBS 0335-052, the most probable young galaxy in formation).

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Star-Gas Misalignment in Galaxies: II. Origins Found from the Horizon-AGN Simulation

  • Khim, Donghyeon J.;Yi, Sukyoung K.
    • 천문학회보
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    • 제46권1호
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    • pp.29.1-29.1
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    • 2021
  • There have been many studies aiming to reveal the origins of the star-gas misalignment found in galaxies, but there still is a lack of understanding of the contribution from each formation channel candidate. We explore the properties, origins, and lifetimes of the star-gas misalignment using Horizon-AGN, a large-volume cosmological simulation. First, the misalignment fraction shows a strong anti-correlation with the kinematic morphology (V/sigma) and the cold gas fraction of the galaxy. This result is consistent with the result of integral field spectroscopy observations. Second, we have identified four main formation channels of misalignment and quantified their level of contribution: mergers (35%), interaction with nearby galaxies (23%), interaction with dense environments or their central galaxies (21%), and secular evolution including smooth accretion from neighboring filaments (21%). Third, the decay timescale of the misalignment is strongly linked with the kinematic morphology of the galaxy: early-type galaxies (2.28 Gyr) tend to have a longer misalignment lifetime than LTGs (0.49 Gyr). We also found that the morphology and cold gas fraction are both and independently anti-correlated with the misalignment lifetime.

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Paradigm Forces in English Derivational Morphology

  • Kim, Jin-Hyung
    • 한국영어학회지:영어학
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    • 제1권2호
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    • pp.243-272
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    • 2001
  • This paper focuses on the applicability of paradigm to derivational morphology and the pressure of paradigm enforced on derivational phonology and morphology. Through a close examination of well-attested data, we will demonstrate that apparent surface idiosyncrasies in phonology are the results of paradigm leveling, and that paradigmatic forces of analogy are productively operating in English word formation. On the basis of these observations, it can be argued that the notion of paradigm has at least some justification within derivational morphology as well, even if not to the same extent that it has with inflectional morphology and that the paradigm forces are independently needed in any adequate phonological and morphological theory. This can also be extended to provide evidence against the split morphology hypothesis that inflectional and derivational morphology belong to different grammatical modules.

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