• Title/Summary/Keyword: Morphological Evolution

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STAR FORMATION ACTIVITY OF GALAXIES IN A NEARBY COMPACT GROUP: THE NGC 4095 GROUP

  • POOJON, PANOMPORN;SAWANGWIT, UTANE;KRIWATTANAWONG, WICHEAN
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.507-509
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    • 2015
  • This work aims to study the evolution of galaxies, located in the dense environment of the NGC 4095 compact group, which have recession velocities 6,000 < v ($km\;s^{-1}$) < 8,000. Imaging observations for BV $R_c$ broad-band, and [$S\small{II}$] and red-continuum narrow-band were carried out with the 2.4 m Thai National Telescope (TNT) at Doi Inthanon, Chiang Mai, Thailand. The sample contains 13 galaxies, consisting of 8 spirals, 4 ellipticals and 1 irregular morphological type. Late type galaxies tend to be bluer than early type galaxies. The results show that most of the late type galaxies have ongoing star formation activity, which could be triggered by galaxy-galaxy or tidal interactions, and that young massive stars in these galaxies cause their colors to be bluer than the early type galaxies.

Synthesis of Monodispersed Barium Titanate Nanopowders by Alkoxide-Hydroxide Sol-Precipitation Method

  • Yoon, Song-Hak;Kim, Min-Gyu;Shin, Nam-Soo;Kim, In-Sung;Baik, Sung-Gi
    • Journal of the Korean Ceramic Society
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    • v.43 no.11 s.294
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    • pp.710-714
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    • 2006
  • Barium titanate nanoparticles were synthesized under N$_2$ atmosphere by the hydrolysis and condensation of barium hydroxide octahydrate and titanium (IV) isopropoxide. The synthesized particles were aggregates of nanosized primary particles. The primary particles of about 20-50 nm in diameter became building blocks of larger secondary particles, which are in most cases spherical in shape. The size and morphological evolution of secondary particles are strongly related to the precursor concentration. The observations suggest that formation and control of secondary particles is an essential step in the alkoxidehydroxide sol-precipitation process to obtain monodispersed barium titanate nanopowders.

Phase stability and Morphology of high-k gate stack of $Si/SiO_2/HfO_2$ and $Si/SiO_2/ZrO_2$

  • Lee, Seung-Hwan;Bobade, Santosh M.;Yoo, W.J.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.11a
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    • pp.118-119
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    • 2007
  • Phase stability and morphological investigation on the $Si/SiO_2/HfO_2$ and $Si/SiO_2/ZrO_2$ stack are presented. Thermal stability of $HfO_2$ and $ZrO_2$ determines the quality of interface and subsequently the performance of device. The stacks have been fabricated and annealed at $1000^{\circ}C$ for various time. In evolution of crystalline phase and morphology (electrical and geometrical) of high-k materials, annealing time and process are observed to be crucial factors. The crystallization of some phase has been observed in the case of $Si/SiO_2/HfO_2$. The chemical environment around Zr and Hf in respective samples is observed to be different.

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Taxonomic Study on Spider Mites (Tetranychidae ; Acarina ) of Korea (한국산 응애과 (거미속 : 진드기목) 의 분류학적 연구)

  • 이원구;이병훈;김영진
    • Animal Systematics, Evolution and Diversity
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    • v.2 no.2
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    • pp.13-26
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    • 1986
  • A Taxonomic investigation was carried out on the following seven spider mites (Family tetranychidae) by comparison of morphological characters, cuticular lobes and karyotypes. Materials used in this study were collected and reared at Jeonju, Jorea during October 1985-June 1986. Subfamily Bryobiinae ; Bryobia praetiosa Koch, 1836 ; Petrobia latens (Mller, 1776). Subfamily Tetranychinae ; Panonychus citri (McGregor , 1919) ; P.ulmi (Koch, 1836): T vienensis tranychus Zacher , 1920 ; T.urticae (Koch, 1836) ; T. kanzawai Kishida , 1927. Of them two species, P. latens and T. kanzawai , are newly recorded from Korea.

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Copidognathus koreanus, a New Species of Halacaridae (Acari) from Korea (한국산 짠물응애과(진드기목)의 1신종, Copidognathus koreanus)

  • Tapas Chatterjee;Cheon Young Chang
    • Animal Systematics, Evolution and Diversity
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    • v.19 no.1
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    • pp.95-102
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    • 2003
  • A new species of Halacaridae, Copidognathus koreanus is recorded from the Korean coast mostly among intertidal coralline algae. The present new species comes close with C.auroroe Newell, C.curtus (Hall), C.richardi (Trouessart) and C.unolaskensis Newell. Morphological similarities and dissimilarities among them are discussed. This is the first report on the marine halacarid mite from Korea.

Taxonomic Status of Silpha perforata(Coleoptera: Silphidae) from Jejudo Is., Korea (제주도산 넓적송장벌레 (딱정벌레목: 송장벌레과) 에 대한 분류학적 검토)

  • Cho, Young-Bok;Park, Sei-Woong;Massaki Nishikawa;Kwon, Yong-Jung
    • Animal Systematics, Evolution and Diversity
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    • v.20 no.1
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    • pp.63-71
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    • 2004
  • The clustering analysis and comparison of male genitalia of Silpha perforata complex were carried out to decide the taxonomic status of the population from Jejudo Is., Korea. One hundred and five individuals from Korea, Japan, and China were examined for the present study. Based on the result, the population of Jejudo Is. was treated as intraspecies of Silpha perforata with a morphological variation.

New Record of Two Echinoids (Echinodermata, Echinoidea) in Korea (한국산 성게류 (극피동물문, 해담강)의 2미기록종)

  • Shin, Sook
    • Animal Systematics, Evolution and Diversity
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    • v.16 no.2
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    • pp.219-226
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    • 2000
  • Some echinoids were collected at about 20m depth of the sea in Moseulpo of Jejudo Island. Among them two species, Diadema setosum (Leske, 1778) and Toxopneu-stes pileolus(Lamarck, 18716), turned out to be new to the Korean fauna. They were redescribed on the morphological characteristics with illustrations. The order Diadematoida is new to Korea. Fourteen echinoids species so far have been report-ed from the sea around Jejudo Island in Korea.

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Taxonomic Notes on the Genus Delta de Saussure (Hymenoptera: Vespidae: Eumeninae) from Vietnam

  • Nguyen, Lien Thi Phuong
    • Animal Systematics, Evolution and Diversity
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    • v.31 no.2
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    • pp.95-100
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    • 2015
  • A taxonomic study of the genus Delta de Saussure, 1855 from Vietnam is presented. A total of four species are recorded: D. campaniforme campaniforme (Fabricius, 1775), D. conoideum (Gmelin, 1790), D. esuriens esuriens (Fabricius, 1787), and D. pyriforme pyriforme (Fabricius, 1775). Of these, D. campaniforme campaniforme was first recorded from Vietnam by de Saussure et al., 1904, under the name Eumenes esuriens and is now reconfirmed to occur in Vietnam after more than 100 years, and D. conoideum is newly recorded from Vietnam. A key to species based on morphological characters is given with illustrations, and distributional records in Vietnam are also provided.

New Records of Two Zooxanthellate Scleractinian Corals (Anthozoa: Hexacorallia: Scleractinia) from Korea

  • Choi, Eunae;Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.31 no.2
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    • pp.86-94
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    • 2015
  • The two zooxanthellate scleractinian corals are newly recorded in Korea: Psammocora albopicta Benzoni, 2006 of the family Psammocoridae and Oulastrea crispata (Lamarck, 1816) of the family Faviidae. These families are also newly recorded in Korea. Specimens were collected from the subtidal zones of Jeju-do Island, Korea by SCUBA diving from 1999 to 2014. Two scleractinians are described based on the morphological characters of skeletal structures. Psammocora albopicta is distinguished by its encrusting cerioid growth form, high density of corallites, small calicular diameter, single styliform columella, and fewer rows of enclosed septa. Oulastrea crispata is characterized by its encrusting plocoid growth form, polygonal calicular shape, irregular paliform lobes, and papillose columella.

Intraspecific Phylogeny of the Korean Water Deer, Hydropotes inermis argyropus (Artiodactyla, Cervidae)

  • Kim, Hye Ri;Kim, Eui Kyung;Jeon, Mi Gyung;Park, Yung Chul
    • Animal Systematics, Evolution and Diversity
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    • v.31 no.2
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    • pp.118-121
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    • 2015
  • The water deer, Hydropotes inermis (Cervidae), is native to China and Korea and has two subspecies of the Chinese water deer (Hydropotes inermis inermis) and Korean water deer (Hydropotes inermis argyropus). To date, only the Korean water deer has been reported in South Korea. In this study, however, an intraspecific phylogeny and haplotype analysis based on mitochondrial cytochrome oxidase I indicated that both Korean and Chinese water deer are found in South Korea. The populations of the two Korean genetic lineages did not show distinct geographic distributions. Further morphological studies on the Korean water deer will be required to confirm its taxonomic status.