• Title/Summary/Keyword: transitional type

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Chemical properties of star-forming galaxies in Virgo-related large-scale filamentary structures.

  • Chung, Jiwon;Rey, Soo-Chang;Kim, Suk;Lee, Youngdae;Sung, Eon-Chang
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.75.3-75.3
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    • 2019
  • The filament is an interesting structure in the Universe because clusters form at the nodes of filaments and grow through the continuous accretion of individual galaxies and groups from the surrounding filaments. We study the chemical properties of star-forming (SF) galaxies in the five large-scale filamentary structures (Leo II A, Leo II B, Leo Minor, Canes Venatici, and Virgo III) related with the Virgo cluster, with the spectroscopic data taken with the SDSS DR12, and compare them with those of the Virgo cluster and field galaxies. In mass-metallicity relation, most of the SF galaxies in Virgo-related filaments (except Virgo III filament) show lower metallicity on average than the Virgo cluster SF galaxies, but similar to field counterparts. These chemically less evolved feature of SF galaxies in the filaments and field are more pronounced for lower mass galaxies. This is probably because low mass galaxies have low potential wells and are therefore likely to be sensitive to cluster environmental effects. Interestingly, we find that the metallicity enhancement of SF galaxies in the Virgo III filament. In chemical and morphological perspectives, SF galaxies in the Virgo III thought to be transitional objects possibly transformed from SF late-type galaxies and are on the way to red early-type galaxies in the filament environment. This is the first discovery of systematic 'chemical pre-processing' signature for filament galaxies in Local Universe before they fall into the cluster.

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Ultraviolet Color-Magnitude Relations of Early-type Dwarf Galaxies in the Viro Cluster

  • Kim, Suk;Rey, Soo-Chang;Sung, Eon-Chang;Jerjen, Helmut;Lisker, Thorsten;Lee, Youngdae;Chung, Jiwon;Yi, Wonhyeong;Park, Mina
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.47.2-47.2
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    • 2013
  • We present ultraviolet (UV) color-magnitude relations (CMRs) of early-type dwarf galaxies in the Viro cluster, combining Galaxy Evolution Explorer (GALEX) UV data with SDSS optical data, based on the Extended Virgo Cluster catalog (EVCC). We find that dwarf lenticular galaxies (dS0s) show a surprisingly distinct and tight locus separated from that of ordinary dEs, which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. The observed CMR of dS0s is well matched by models with relatively long delayed star formation. The dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment. Most early type dwarf galaxies with blue UV colors (FUV-r < 6 and NUV-r < 4) are identified as those showing spectroscopic hints of recent or ongoing star formation activities. In any case UV photometry provides a powerful teel to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories. lenticular galaxies, and irregular high surface brightness (HSB) galaxies, respectively. Dwarf elliptical galaxies and dwarf irregular LSB galaxies occupy the similar structural parameter spaces. We suggest that giant elliptical galaxies and dwarf elliptical galaxies may have different origin.

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OLOR-MAGNITUDE RELATIONS OF EARLY-TYPE DWARF GALAXIES IN THE VIRGO CLUSTER: AN ULTRAVIOLET PERSPECTIVE

  • Kim, Suk;Rey, Soo-Chang;Lisker, Thorsten;Sohn, Sangmo Tony
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.38.2-38.2
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    • 2010
  • We present ultraviolet (UV) color-magnitude relations (CMRs) of early-type dwarf galaxies in the Virgo cluster, based on Galaxy Evolution Explorer (GALEX) UV and Sloan Digital Sky Survey (SDSS) optical imaging data. We find that dwarf lenticular galaxies (dS0s), including peculiar dwarf elliptical galaxies (dEs) with disk substructures and blue centers, show a surprisingly distinct and tight locus separated from that of ordinary dEs, which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. We also find that the UV CMRs of dEs in the outer cluster region are slightly steeper than that of their counterparts in the inner region, due to the existence of faint, blue dEs in the outer region. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. We confirm that the feature of delayed star formation of early-type dwarf galaxies in the Virgo cluster is strongly correlated with their morphology and environment. The observed CMR of dS0s is well matched by models with relatively long delayed star formation. Our results suggest that dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment, In any case, UV photometry provides a powerful tool to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories.

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A Study on the Change of Da-bo Stupa in Dunhuang Mogao Grottoes (돈황 막고굴에 나타난 다보탑의 변천)

  • Cho, Jeong-Sik;Kim, Bue-Dyel;Jo, Jae-Hyun;Kim, Bo-Ram
    • Journal of architectural history
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    • v.22 no.5
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    • pp.23-35
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    • 2013
  • This study aims to investigate the architectural characteristics of the Da-bo stupa by examining the correlation among architectural languages and by studying the features of its architectural components and transitional changes shown in Da-bo stupa line drawings in Dunhuang Mogao Grottes. The results are as follows. 1st, the Da-bo stupa of Dunhuang faithfully follows the sutra of lotus, and although the form changes, the fundamental essence of Bo-tap-yong-chul and two seated Buddhas provided by the Gyun-bo-tap-pum in the sutra of lotus is consistent. 2nd, the pagoda body can be periodically divided into parasol, stupa, and royal palace types. The parasol type has an incomplete tower body, which makes distinguishing each of its architectural components difficult. The stupa type appeared between the early (AD 618-712) and middle (AD 766-835) Tang dynasty. It combines the form of Indian stupa type and East Asian wood structural architecture. The royal palace type, which appeared between the peak period of the Tang (713-765) and Sung Dynasties, shows the standardized pattern of the Da-bo stupa described as two seated Buddhas and Bo-tap-yong-chul. 3rd, the use of a stylobate does not appear in the early construction of Da-bo stupa, only in the later period, in the form of high pillars. Forms include many Su-mi-jwah and three-way stairways and Dab-do, but as time passes, the forms are simplified to the form of high pillars. 4th, the purpose of early Da-bo stupa was to provide space for Da-bo-yu-rae of Gyun-bo-tap-pum; hence, it did not have sangryoon(the top part). However, after it was influenced by general pagodas, sangryoon was established. Toward the Tang Dynasty, sangryoon has come to emphasize the forms of boryoon(nine wheels) or dome. However, this form is eventually simplified to only retain bo-joo(the orb).

A Study on Deep Geothermal Energy and Potential of Geothermal Power Generation in Mongolia (몽골의 심부 지열에너지 자원과 지열발전에 관한 연구)

  • Hahn, Jeong-Sang;Yoon, Yun-Sang;Kiem, Young-Seek;Hahn, Chan;Park, Yu-Chul;Mok, Jong-Gu
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.8 no.3
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    • pp.1-11
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    • 2012
  • Mongolia has three(3) geothermal zones and eight(8) hydrogeothermal systems/regions that are, fold-fault platform/uplift zone, concave-largest subsidence zone, and mixed intermediate-transitional zone. Average temperature, heat flow, and geothermal gradient of hot springs in Arhangai located to fold-fault platform/uplift zone are $55.8^{\circ}C$, 60~110 mW/m2 and $35{\sim}50^{\circ}C/km$ respectively and those of Khentii situated in same zone are $80.5^{\circ}C$, 40~50 mW/m2, and $35{\sim}50^{\circ}C/km$ separately. Temperature of hydrothermal water at depth of 3,000 m is expected to be about $173{\sim}213^{\circ}C$ based on average geothermal gradient of $35{\sim}50^{\circ}C/km$. Among eight systems, Arhangai and Khentii located in A type hydrothermal system, Khovsgol in B type, Mongol Altai plateau in C type, and Over Arhangai in D type are the most feasible areas to develop geothermal power generation by Enhanced Geothermal System (EGS). Potential electric power generation by EGS is estimated about 2,760 kW at Tsenher, 1,752 kW at Tsagaan Sum, 2,928 kW at Khujir, 2,190 kW at Baga Shargaljuut, and 7,125 kW at Shargaljuut.

The Types and Characteristics of Transformational Design Ideas in Contemporary Military Look (현대 밀리터리 룩에 나타난 전환적 디자인 발상 유형과 특성)

  • XUEJIAO, JIA;Kim, Hyun-joo;Youn, Ji-young
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.265-275
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    • 2022
  • This study analyzes and categorizes the cases of military look's transitional design ideas in recent women's fashion collections, and derives characteristics. The research method is a theoretical review of military look and an analysis of fashion collection cases. The research results were classified into a total of six transformational design ideas. As a structural change in design, it is a decentralized type, a type of expansion and reduction, a change in the entire material, or a transition of some materials, and finally a type according to heterogeneous harmony and organic combination corresponding to styling. Finally, a total of three characteristics are the reconstruction of structural elements, the expansion of the metric of the second mix match, and the emotional fusion of styling. I hope that the study of the transformative type of idea of the new military look will be the driving force for creative design development and will be a basic study that can read the current status and changes of the times throughout fashion design.

EXPERIMENTAL STUDY ON THE ANTERIORLY DISPLACED TEMPOROMANDIBULAR JOINT MENISCUS IN RABBIT (실험적으로 전방이동시킨 가토의 악관절원판에 관한 연구)

  • Choi, Nack-Jun;Chang, Young-Il
    • The korean journal of orthodontics
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    • v.21 no.1 s.33
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    • pp.53-76
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    • 1991
  • The study was designed to analyse the reorganization of the rabbit TMJ meniscus which was anteriorly displaced by surgery. The author compared the anteriorly displaced groups with control group. After surgical opening of the left rabbit TMJ space, cut the posterior attachment of the meniscus, and pushed it under the undercut area of the condyle head. Experimental groups were sacrificed by 1, 2, 4, 8 weeks after surgery. The samples were analysed with light microscope under T-B stain and electron microscope. The results were as follows: 1) The rabbit TMJ meniscus consisted of thick anterior and posterior band running different way, and comparative thin intermediate band runining antero-posteriorly. 2) Round oval shape chondrocyte-like cells were imbeded between the collagen fiber bundles and composed of proteoglycan granules, that showed metachromasia with toluidine blue, around the cell matrix. 3) Type II collagen fiber bundles in experimental group occured degenerative changes in organic patterns at 8 weeks, but those of type I collagen fiber bundles sustained longer, 4) The typical fibrocartilage of the rabbit TMJ meniscus was changed into fibrotic mode in process of time and showed the degenerative changes, which contained hyperplasia, calcification, resorption and hyalinization in the connective tissue. 5) The hyperplastic change of the synovial membrane in 4 week group and transitional change from fibrocyte to chondrocyte in cell type in 8 week group were observed. 6) The diameters of collagen fibers were diminished with the degenerative changes, the shape of the fibers became wavier and more nonorganic in running pattern and fiber bundle spaces widened.

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Anal Fistula and Perianal Abscess in Pediatric and Adolescent Patients (소아 및 청년층의 치루와 항문주위농양)

  • Kim, Soong-Chul;Kim, Jin-Cheon;Kim, In-Koo
    • Advances in pediatric surgery
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    • v.1 no.1
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    • pp.40-45
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    • 1995
  • Anal fistula and perianal abscess in pediatric patients have been reported to have several characteristics, e.g. prevalent in less than 2 years of age, male preponderance, straight course of tract, and low type of fistula. We performed a retrospective study of twenty nine pediatric patients to see these characteristics comparing with the transitional age group of adolescents. Between June 1989 and December 1993, twenty-nine pediatric (<15year-old) and sixteen adolescent patients(${\geqq}$15, <25 year-old) with anal fistula and perianal abscess were treated by surgical intervention. Perianal abscess and anal fistula in the pediatric group had the predilection for male(100%), age less than two years (72.4%), low type(100%), and lateral localization(87.5%). But the features of the adolescent group were similar to those of adult. Twenty-one(87.5%) and 10(66.7%) enteric bacterial colonies were isolated from 16 pediatric and 11 adolescent patients, respectively. Considering the predominance of low type and the organisms cultured in the pediatric group, crypt-glandular infection seems to be a major preceding event. Incision and drainage were sufficient for cure in 15 among 16 perianal abscesses, and fistulas were cured by either fistulotomy or fistulotomy in all the 14 patients. The importance of effective drainage of perianal abscess and fistulotomy including internal opening cannot be overemphasized.

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A Study on the Ultrastructure of Reproductive Organ of Korean Planaria (Dugesia japonica) (한국산(韓國産) 플라나리아(Dugesia japonica Ichikawa et Kawakatsu)생식기관(生殖器官)의 미세구조(微細構造)에 관(關)한 연구(硏究))

  • Chang, N.S.;Kim, W.K.
    • Applied Microscopy
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    • v.15 no.1
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    • pp.31-58
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    • 1985
  • The morphological study on different types of cells of reproductive organ including spermatogenesis in the adult planaria was performed to observe their cytochemical and ultrastructural characteristics. 1. Spermatogenesis The circular luminated material appears immediately inside the nuclear envelope of early spermatid and is found also in the nucleus of sperm, but typical acrosomal structures cannot be observed. Approximately ten of small-sized mitochondria occur around the nucleus in the transitional phase from primary spermatocyte to secondary spermatocyte, but in sperm a long mitochondrion is closely associated with nucleus, parellel to long axis of it. The sperm has a relatively long head connected with two tails via hollow neck. 2. Reproductive organ The penis bulb and the bursa stalk were observed. (1) Penis bulb The cells constituted penis bulb are classified into six types on the basis of ultrastructure of the cells and cytochemistry of the cytoplasmic granules. 1) A-type cells: These cells exhibiting low electron density are mainly occupied by large nucleus. These cells possess two different types of granules: highly electron-dense round granules with an average size of $0.9{\mu}m$, and electron-dense granules exhibit PAS-positive reaction. 2) B-type cells contain PAS-positive granules with the size of about $0.4{\mu}m$. They are rich in free ribosomes and mitochondria. 3) C-type cells are found to be dark cells due to high electron-density. These cells are largely occupied by large nucleus. 4) D-type cells: These cells are seen as light cells which have poorly developed cell organelles. 5) E-type tells: These cells contain a large number of glycogen granules which occupy most of cell. 6) F-type cells: These arc parietal epidermal cells surrounding the genital antrum. These cells are characterized by their finger-like shapes and the presence of a number of electron-dense, irregularly-shaped structures inside cells. The relatively large electron-lucent granules can be also found. The F-type cells possess numerous microvilli on their free surfaces. (2) Bursa stalk The cells constituted bursa stalk are classified into 3 types on the basis of cell shapes and presences of electron-dense or electron-lucent granules. 7) G-type cells with a long cytoplasmic process. They have large nuclei and poorly developed cell organelles. 8) H-type cells: These cells are characterized by the presence of a long cytoplasmic process and relatively highly electron-dense cytoplasmic profile. They have poorly developed cell organelles. 9) I-type cells contain large electron-lucent granules which exhibit negative reactions with three kinds of cytochemical staining methods used in this experiment. The fine electron-dense structures can be found inside these granules.

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Geochemical Characteristics of Allanite from Rare Metal Deposits in the Chungju Area, Chungcheongbuk-Do (Province), Korea (충주지역 희유원소광상에서 산출되는 갈렴석의 지구화학적특성)

  • Park, Maeng-Eon;Kim, Gun-Soo;Choi, In-Sik
    • Economic and Environmental Geology
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    • v.29 no.5
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    • pp.545-559
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    • 1996
  • Rare metal (Nb-Zr-REE) ore deposits are located in the Chungju area. Geotectonically, the rare metal ore deposits are situated in the transitional zone between Kyeonggi massif and Okcheon belt. The rare metal deposits are distributed in Kyemyeongsan Formation which consist of schist and alkaline igneous rocks. Alkali granite has suffered extensive post-magmatic metasomatism and hydrothermal processes. The ore contains mainly Ce-La, Ta-Nb, Y, Y-Nd, Nd-Th group minerals. More than 15 RE and REE minerals are found in the ore deposits. Allanite, one of the Ce-La rich REE minerals belonging to the epidote group, is the most common mineral in the studied area. The allanite- bearing rocks may be devided into seven types by features of occurrence and mineral associations; zircon type (ZT), allanite-vein type (AT), feldspar type (KT), fluorite type (FT), quartz-mica type (QT), iron-oxide type (MT), and amphibole type (HT). The allanite veins (AT) and zircon rich rocks (ZT) contain the highest total REE contents. Differences in REE abundance can be interpreted in terms of varying portions of magmatic hydrothermal fluid. Petrographical and chemical data are presented for allanites which were collected from different types. The allanites show wide variations in optical properties, due in part to differences in their chemical composition (depending on the types) and to the degree of crystallinity of the individual specimens. Allanite metamicts in biotite are generally surrounded by well developed pleochroic haloes. Usually, allanite is accompanied by zircon and other REE-bearing minerals. CaO and total REE contents $({\sum}RE_2O_3)$ range from 9.29 to 18.79% and 11.66 to 26.31%, respectively. Also, SiO, (28.87~32.61%), $Al_2O_3$ (8.30~16.88%), and $Fc_2O_3$ (16.74~24.38%) contents show varying contents from type to type. The ${\sum}RE_2O_3$ of allanite has positive relationships with $Fe_2O_3$ and negative relaton with CaO, $SiO_2$, and $Al_2O_3$ Backscattered electron microscope images (BEl) of allanite shows that the its mineral composition and texture is very complex. The allanite-bearing hosts show distinct light REE enrichment with strong negative Eu anomaly except for HI. The HT has an almost flat REE distribution pattern with a small negative Eu anomaly. The chemical variation of the allanites with occurrences and mineral association can be related to condition of temperature and oxidation states in precipitation environment.

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