• Title/Summary/Keyword: External morphology

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A Taxonomic and Ecological Study of Gloiopeltis furcata J. Agardh (Rhodophyta) in Korea

  • Lee, Jae-Won
    • Journal of Plant Biology
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    • v.38 no.2
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    • pp.165-171
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    • 1995
  • Plants of G. furcata were divided into four variant populations. The habit characteristics, external and internal morphology were analysed quantitatively in order to clarify their morphological variation. Among four variant populations, type I(typical G. furcata type) and type II(G. furcata f. intricata type) may be influenced by the time when the develop from the crustose basal discs and the tidal level. Type III is the immature plants, and type IV (G. furcata f. coliformis type) is a G. furcata population in late spring after the luxuriant season. For the reason, the formas of G. furcata f. intricata and f. coliformis are no more valid in Gloiopeltis furcata.

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Influence of in-situ remote plasma treatment on characteristics of amorphous indium gallium zinc oxide thin film-based transistors

  • Gang, Tae-Seong;Gu, Ja-Hyeon;Hong, Jin-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.257-257
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    • 2011
  • The amorphous indium-gallium-zinc-oxide (a-IGZO) materials for use in high performance display research fields are strongly investigated due to its good performance, such as high mobility and better transparency. However, the stability of a-IGZO materials is increasingly becoming one of critical issues due to the sub-gap electron trap sites induced by rough interfaces during deposition processing. It is well-known that the threshold voltage shift is related to interface roughness and oxygen vacancy formed by breaking weak chemical bonds. Here, we report the better properties of transparent oxide transistors by reducing the threshold voltage shift with an external rf plasma supported magnetron sputtering system. Mainly, our sputtering method causes the surface of sample to be sleek, so that it prevents the formation of various defects, such as shallow electron trap sites in the interface. External rf power was applied from 0 to 50W during RF sputtering process to enhance the stability of our oxide transistor without having a large voltage shift. To observe the effects of external rf-plasma source on the properties of our devices, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) are carried out to observe surface roughness and morphology of sputtered thin film. In addition, typical electrical properties, such as I-V characteristics are analyzed.

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A HIGHLY DISTURBED MOLECULAR CLOUD S287: I. CO OBSERVATIONS AND KINEMATICS

  • LEE YOUNGUNG
    • Journal of The Korean Astronomical Society
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    • v.27 no.2
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    • pp.147-158
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    • 1994
  • We have obtained high angular resolution maps toward a molecular cloud associated with an HII region S287 and studied mainly kinematics of the cloud. The mapped region is 1.5 square degrees of the cloud in the transitions of $^{12}CO\;and\;^{13}CO\;J=1-0$. We have obtained a large range of mass, $1.3\times10^4M_\bigodot$, to $7.2{\times}10^4M_{\bigodot}$ using three different techniques. The S287 molecular cloud shows a very disturbed feature: velocity field of the cloud is very complicated, and shows several arcs. It is likely that the southern part of cloud is being disrupted by the residing HII region S287 as well as external perturbing sources. In addition to an HII region, five bipolar outflows are also disturbing the molecular gas significantly. The large virial mass and the very disturbed morphology may reflect the fact that the cloud is not gravitationally bound system, as in the case of nearby giant molecular cloud (GMC) G216-2.5. The several arc structure and the filamentary features are possibly driven by external strong stellar winds, and these external perturbing sources may be driving the second generation of star-forming activities on the edges of the S287 molecular cloud.

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산화아연 압전 나노전력발전소자 기반 에너지 하베스팅

  • Kim, Sang-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.49-49
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    • 2010
  • Nanopiezotronics is an emerging area of nanotechnology with a variety of applications that include piezoelectric field-effect transistors and diodes, self-powered nanogenerators and biosystems, and wireless nano/biosensors. By exploiting coupled piezoelectric and semiconducting characteristics, it is possible for nanowires, nanobelts, or nanorods to generate rectifying current and potential under external mechanical energies such as body movement (handling, winding, pushing, and bending) and muscle stretching, vibrations (acoustic and ultrasonic waves), and hydraulic forces (body fluid and blood flow). Fully transparent, flexible (TF) nanogenerators that are operated by external mechanical forces will be presented. By controlling the density of the seed layer for ZnO nanorod growth, transparent ZnO nanorod arrays were grown on ITO/PES films, and a TF conductive electrode was stacked on the ZnO nanorods. The resulting integrated TF nanodevice (having transparency exceeding 70 %) generated a noticeable current when it was pushed by application of an external load. The output current density was clearly dependent on the force applied. Furthermore, the output current density depended strongly on the morphology and the work function of the top electrode. ZnO nanorod-based nanogenerators with a PdAu, ITO, CNT, and graphene top electrodes gave output current densities of approximately $1-10\;uA/cm^2$ at a load of 0.9 kgf. Our results suggest that our TF nanogenerators are suitable for self-powered TF device applications such as flexible self-powered touch sensors, wearable artificial skins, fully rollable display mobile devices, and battery supplements for wearable cellular phones.

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A Study on External.Internal Morphology and Pattern Analysis of Atractylodes Rhizomes (출류(朮類) 한약재의 외.내부형태와 이화학패턴 연구)

  • Kim, Jung-Hoon;Lee, Guem-San;Choil, Goya;Hwang, Sung-Yeoun;Kim, Hong-Jun;Jeong, Seung-Il;Ju, Young-Sung
    • The Korea Journal of Herbology
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    • v.24 no.2
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    • pp.77-85
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    • 2009
  • Objectives : To determine the discriminative criteria for Atractylodes rhizomes, the experiment of externalinternal characteristics and physicochemical pattern analysis were performed. Methods : External characteristics was observed using stereoscope. The sectioned materials which were covered with parffin were stained by Ju's method. Physicochemical patterns were analyzed using HPLC/DAD. Results : 1. External shape of original plant : Atractylodes maaocephala and A. japonica had relatively long petioles and 3-5 parted leaves. A. macrocephala had big purple flowers whereas A. japonica had relatively small white flowers and pinnate bracts. A. lancea had sessile leaves and white flowers, and the end parts of degenerated stamens were bent. 2. External shape of herbal medicine: A. macrocephala which was fist-shaped rhizome had pa-pillate processes and the cross section was light gray and sulcate. A. japonica and A. lancea were connected-beady or tubercular rhizomes, and the cross sections were both yellow-colored white. However, the cross section of A. japonica was fibrous, the width of cortex was narro-wer than that of stele, and radial shape in cortex was rare, whereas the width of cortex in A. lancea was similar to that of stele in size, and radial shape in cortex was obvious. 3. Internal shape of herbal medicine: A. macrocephala and A. lancea did not have lignified fascicles in cortex. However, the vascular bundles and vessels of A. macrocephala were wedge shaped and radial arrangement, and vascular bundles were densely populated in stele whereas those of A. lancea were repeatedly arranged and thinly extended to cortex. A. japonica had lignified fascicles in cortex and the width of vascular bundles was conspicuously thick with narrow intervals. 4. Physicochemical pattern analysis : A. macrocephala and A. lancea contained atractylenolide I and atractylenolide Ill whereas A. japonica contained atractylenolide I, atractylenolide Ill. diacetyl-atractylodiol, compound-4, compound-5. The three species of Atractylodes rhizomes showed different chromatogram patterns. Conclusions : The results could be used as discriminative criteria for Atractylodes rhizomes and as fundamental materials to researches of further pattern analysis and biological reaction.

A Study of the Internal and External Morphology in the Mandibular first Premolar of the Middle-Aged Korean Using a Microcomputed Tomography (미세단층촬영기를 이용한 중년 한국인 하악 제1소구치의 내 외부 형태학 연구)

  • Chun, K.J.;Lee, H.J.;Lee, Jong-Yeop
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.4
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    • pp.254-261
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    • 2005
  • Dental statistics for Koreans are far from complete and the majority of previous researches have adopted techniques such as radiological analysis and sectioning of teeth for morphological information, which are time-consuming, less accurate and destructive. Thus, a new nondestructive method is necessary to get precise dental standardization data for Koreans. For the above purpose, each of the first premolars was scanned by a micro-CT (SkyScan, Belgium) with a resolution of $21.31{\mu}m$ at an interval of 0.022mm along the plane horizontally parallel to an occlusion plane. Internal and external morphological sections were measured and compared to the values in the average tooth size table for permanent teeth presented by G. V Black.

Taxonomic position of Pedicularis hallaisanensis Hurusawa, an endemic plant of Mt. Halla (한라산 고유 한라송이풀의 분류학적 위치)

  • Cho, Won-Bum;Choi, Byoung-Hee
    • Korean Journal of Plant Taxonomy
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    • v.41 no.2
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    • pp.130-137
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    • 2011
  • Pedicularis growing at Mt. Halla of Jeju Island is known as an endemic species of P. hallaisanensis Hurusawa. On the other hand, the plant is morphologically similar to P. amoena, P. spicata, and P. verticillata in gross morphology, so the taxonomic treatment of the taxon remains controversial. To clarify the taxonomic position of the plants, we examined external morphological characters and nuclear ribosomal DNA ITS sequences for P. hallaisanensis and its related species. The plants of Mt. Halla are clearly different from P. amoena and P. verticillata in the morphology of calyx lobes, the length of galea and lower lip, density of glandular hairs on plants, presences of the radical leaves after anthesis and molecular data. However, P. hallaisanensis is not clearly separated from P. spicata distributed in N. E. Asia on external morphological characters and DNA sequences of internal transcribed spacers. In this study, the morphological and molecular data suggested that P. hallaisanensis should be merged into the former species.

External Morphology and Species Components of the White Grubs Collected from Ginseng Field and Its Neighbouring Fallows (인삼포(人蔘圃) 및 그 주변 포장(圃場)에서 채집(採集)된 굼뱅이의 종구성(種構成) 및 외부형태(外部形態))

  • Kim, K.H.;Kim, S.S.;Hyun, J.S.
    • Korean journal of applied entomology
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    • v.24 no.4 s.65
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    • pp.179-182
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    • 1986
  • The white grubs were collected from ginseng field and fallow lands to examine their external morphology and species components. They were divided into 3 subfamilies, i.e., Melolonthinae, Rutellinae, and Sericinae by the shape of anal slit and/or presence of elevated lines in stridulating area of mandible. Eight species were identified by means of comparing the shape of anal slit, setal arrangement of decasternite, and frontoepicranial series of setae. Larvae of Holotrichia diomphalia and H. morosa were observed to damage ginseng root in field.

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Morphological Characteristics between New-born and Over-wintered Populations of the Giant Water Bug (Lethocerus deyrollei: Belostomatidae, Hemiptera) (월동 전후 물장군(Lethocerus deyrollei: 물장군과, 노린재목) 개체군의 형태적 특징)

  • Kim, Seon-Yi;Yoon, Tae-Joong;Kim, Dong-Gun;Jo, Shin-Il;Bae, Yeon-Jae
    • Korean journal of applied entomology
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    • v.47 no.2
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    • pp.111-115
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    • 2008
  • This study was conducted to distinguish adult morphology of the giant water bug (Lethocerus deyrollei) between over-wintered (OLD) and new-born (NEW) populations using materials collected from Gyodong island in Gyeonggi-do, Korea, as well as individuals reared in the laboratory (LAB population) as a control. As a result, no fundamental differences were found in external body structure between OLD, NEW, and LAB populations. However, marginal area of basal procoxa in ventral prothorax and jointed part of forefemur and foretibia were greatly worn in the OLD population. Mid-claws were shorter than 0.5 times the length of the 2nd mid-tarsus; the membranous margin of hemelytra was greatly worn; and hairs of the 5th abdominal tergum were greatly reduced in the OLD population.

A taxonomic study of the external morphology of the Korean Oldenlandia L. (Rubiaceae) (외부형태 형질에 의한 한국산 백운풀속(Oldenlandia L.)의 분류학적 연구)

  • Nam, Bo Mi;Jang, Yong Seok;Park, Myung Soon;Eom, Jeong Ae;Chung, Gyu Young
    • Korean Journal of Plant Taxonomy
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    • v.40 no.3
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    • pp.145-152
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    • 2010
  • The external morphological characters of the Korean Oldenlandia were reviewed, and numerical analysis of 25 quantitative characters carried out to evaluate the delimitation of the taxa. Among the qualitative characters, the leaf shape, inflorescence, pilose of insde corolla, expansion of capsule apex, and seed shape were used to delimit 5 species of Korean Oldenlandia. As the result of principal component analysis of quantitative characters, O. corymbosa, O. hirsuta and O. strigulosa were evidently separated on a two-dimensional plot by PC1 and PC2, and O. brachypoda and O. diffusa slightly overlapped. However, O. brachypoda was distinctly delimited from O. diffusa by the shape of calyx lobe, the lengths of pedicel, filament and stigma. Also each of those two species was in a group of its own by cluster analysis.