• Title, Summary, Keyword: Morphologies

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Surface Morphologies and Internal Fine Structures of Bast Fibers

  • Wang H. M.;Wang X.
    • Fibers and Polymers
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    • v.6 no.1
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    • pp.6-12
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    • 2005
  • Fiber surface morphologies and associated internal structures are closely related to its properties. Unlike other fibers including cotton, bast fibers possess transverse nodes and fissures in cross-sectional and longitudinal directions. Their morphologies and associated internal structures were anatomically examined under the scanning electron microscope. The results showed that the morphologies of the nodes and the fissures of bast fibers varied depending on the construction of the inner fibril cellular layers. The transverse nodes and fissures were formed by the folding and spiralling of the cellular layers during plant growth. The dimensions of nodes and fissures were determined by the dislocations of the cellular layers. There were also many longitudinal fissures in bast fibers. Some deep longitudinal fissures even opened the fiber lumen for a short way along the fiber. In addition, the lumen channel of the bast fibers could be disturbed or disrupted by the nodes and the spi­rals of the internal cellular layers. The existence of the transverse nodes and fissures in the bast fibers could degrade the fiber mechanical properties, whereas the longitudinal fissures may contribute to the very rapid moisture absorption and desorption.

A study on the MC Carbide Morphologies Directionally Solidified Superalloys (일방향응고 초내열합금에서 MC 탄화물 형상에 관한 연구)

  • Kim, Seung-Eon;Jo, Chang-Yong;Kim, Hak-Min
    • 한국기계연구소 소보
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    • pp.57-63
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    • 1990
  • The morphologies of MC carbides (M stands for metal) and creep-rupture properties in directionally solidified Rene 80 having standard and Hf-modified chemistries were studied. It was found that Hf depressed the melting point, $\gamma$- $\gamma$’ eutectic temperature and $\gamma$’ solvus of nickel-base superalloy Rene 80, but did not depress MC carbide forming temperature. The morphologies of MC carbides depended upon solidification sequence, which led to blocky type in the early stage and script type in the late stage of solidification. Creep failure occurs through the crack initiation at the transverse components of longitudinal grain boundaries or interdendritic carbides in directionally solidified superalloys. It could be concluded MC carbide morphologies played an important role in creep properties of DS superalloys, that is, Hf additions increased the creep ductilities and lives of Rene 80.

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FUV Emission-line Morphologies of the SNR G65.3+5.7

  • Kim, Il-Joong;Seon, Kwang-Il;Min, Kyoung-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.70.1-70.1
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    • 2010
  • We present the far-ultraviolet (FUV) emission line morphologies in the whole region of the supernova remnant G65.3+5.7 using the FIMS/SPEAR data. The morphologies of the C IV ${\lambda}{\lambda}1548$, 1551, $H2{\lambda}1608 $, He II ${\lambda}1640$, and O III] ${\lambda}{\lambda}1661$, 1666 lines appear to correlate clearly with the optical emission line images or the ROSAT X-ray (0.11-0.284 keV) image obtained in some of the previous studies. We found that a foreground dust cloud, resonant scattering, and incompleteness of radiative shocks have made the definite differences between the morphologies of the above FUV emission lines. We also present the FUV spectra and line intensities from a few sub-regions.

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Different morphologies of three dimensional ZnO structures synthesized by thermal evaporation method without a catalyst (촉매를 사용하지 않는 열 기화법으로 다양한 형태의 ZnO 3차원 구조체 합성)

  • Bang, Sin Young;Tran, Van Khai;Oh, Dong Keun;Maneeratanasarn, Prachuporn;Choi, Bong Geun;Ham, Heon;Kim, Kyoung Hun;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.1
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    • pp.8-13
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    • 2013
  • ZnO with different morphologies can be used various application depending on their shapes. Different morphologies of ZnO structures were synthesized by a catalysis-free thermal evaporation process. Their morphologies were dependent on the distance from the source to substrate on the same processing condition; in the result were products morphologies of the hollow, cage and star. Their shapes and crystalinity were evaluated by SEM and XRD, respectively. This work demonstrates what kind of growth factors would be involved in the final structure morphologies.

Plasma Textured Glass Surface Morphologies for Amorphous Silicon Thin Film Solar Cells-A review

  • Hussain, Shahzada Qamar;Balaji, Nagarajan;Kim, Sunbo;Raja, ayapal;Ahn, Shihyun;Park, Hyeongsik;Le, Anh Huy Tuan;Kang, Junyoung;Yi, Junsin;Razaq, Aamir
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.98-103
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    • 2016
  • The surface morphology of the front transparent conductive oxide (TCO) films plays a vital role in amorphous silicon thin film solar cells (a-Si TFSCs) due to their high transparency, conductivity and excellent light scattering properties. Recently, plasma textured glass surface morphologies received much attention for light trapping in a-Si TFSCs. We report various plasma textured glass surface morphologies for the high efficiency of a-Si TFSCs. Plasma textured glass surface morphologies showed high rms roughness, haze ratio with micro- and nano size surface features and are proposed for future high efficiency of a-Si TFSCs.

Effects of electroplating parameters on the compositions and morphologies of Sn-Ag bumps (Sn-Ag 범프의 조성과 표면 형상에 영향을 미치는 도금 인자들에 관한 연구)

  • Kim Jong Yeon;Yu Jin;Bae Jin Su;Lee Jae Ho
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • pp.106-109
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    • 2003
  • With the variation of Ag concentration in bath, current density, additive and agitation for electroplating of Sn-Ag solder, the compositions and the morphologies of solder were studied. It was possible to control Ag content in Sn-Ag solder by varying Ag concentration in bath and current density The microstructure size of Sn-Ag solder decreased with increasing current density. Duty cycle of pulse electroplating and quantity of additive affected on Ag content of deposit and surface roughness. In this work eutectic Sn-Ag solder bumps with fine pitch of 30m and height of 15m was formed successfully. The Ag content of electrodeposited solder was confirmed by EDS and WDS analyses and the surface morphologies was analyzed by SEM and 3D surface analyzer.

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Grain Boundary Characteristics and Stress-induced Damage Morphologies in Sputtered and Electroplated Copper Films (스퍼터링 및 전기 도금으로 제조된 구리 박막에서의 표면 결함에 미치는 결정립계의 영향)

  • Park, Hyun;Hwang, Soo-Jung;Joo, Young-Chang
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • pp.4-4
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    • 2003
  • Various Cu films were fabricated using sputtering and electroplating with and without additive, and their surface damages after annealing were investigated. After annealing at 43SoC, the difference between damage morphologies of the films was observed. In some films stress-induced grooves along the grain boundaries were observed, while in the others voids at the grain boundary triple junctions were observed. It was also observed that the stress-induced groove was formed along the high energy grain boundaries. It was found out that the difference of the morphologies of surface damages in Cu films depends on not process type but grain boundary characteristics. To explain the morphological difference of surface damages, a simple parameter considering the contributions of grain structures and grain boundary characteristics to surface and grain boundary diffusions is suggested. The effective grain boundary area, which is a function of grain size, film thickness and the fraction of high energy grain boundaries, played a key role in the morphological difference.

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Measurement of Secondary Electron Emission Coefficient and Bimolecular Valence Band Energy Structure of Erythrocyte with and Without Bioplasma Treatment

  • Lee, Jin-Young;Baik, Guyon;Choi, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.483-483
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    • 2012
  • Recently, nonthermal bioplasma has been attracted by researchers due to their potentials to modulate cellular functions resulting in changes of biomolecular electron band structures as well as cell morphologies. We have investigated the secondary electron emission characteristics from the surface of the erythrocyte, i.e., red blood cell (RBC) with and without the nonthermal bioplasma treatment in morphological and biomolecular aspects. The morphologies have been controlled by osmotic pressure and biomolecular structures were changed by well known reactive oxygen species. Ion-induced secondary electron emission coefficient have been measured by using gamma-focused ion beam (${\gamma}$-FIB) system, based on the quantum mechanical Auger neutralization theory. Our result suggests that the nonthermal bioplasma treatment on biological cells could result in change of the secondary electron emission coefficient characterizing the biomolecular valence band electron energy structures caused by the cell morphologies as well as its surface charge distributions.

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Effect of Martensite Morphology on Damping Capacity and Mechanical Property of Fe-Ni-C Alloys (Fe-Ni-C 마르텐사이트 합금에서 마르텐사이트의 형상이 진동감쇠능과 기계적 성질에 미치는 영향)

  • Lee, Young-Kook;Shin, Han-Chul;Choi, Chong-Sool
    • Journal of the Korean Society for Heat Treatment
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    • v.10 no.3
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    • pp.188-197
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    • 1997
  • Effect of martensite morphology on damping capacity and hardness of Fe-Ni-C martensitic alloys were studied. The morphologies of martensite such as lath, butterfly, lenticular and thin plate were prepared by adjusting nickel content and austenite grain size. The hardness increased in order of lath, lenticular, thin plate, butterfly. The damping capacities of the lath and butterfly martensites were higher than those of the other two morphologies, indicating that the dislocation substructure is more effective in the damping capacity than the twin substructure. Especially, the butterfly martensite showed the highest damping capacity among these morphologies because of presence of not tangled but free dislocations in there.

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A Study on Electrical Resistivity Behaviors of PAN-based Carbon Nanofiber Webs

  • Park, Soo-Jin;Im, Se-Hyuk;Rhee, John-M.;Lee, Young-Seak
    • Carbon letters
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    • v.8 no.1
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    • pp.43-48
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    • 2007
  • The influences of various carbonization temperatures on electrical resistivity and morphologies of polyacrylonitrile (PAN)-based nanofiber webs were studied. The diameter size distribution and morphologies of the nanofiber webs were observed by a scanning electron microscope. The electrical resistivity behaviors of the webs were evaluated by a volume resistivity tester. From the results, the volume resistivity of the carbon webs was ranged from $5.1{\times}10^{-1}\;{\Omega}{\cdot}cm$ to $3.0{\times}10^{-2}\;{\Omega}{\cdot}cm$, and the average diameter of the fiber webs was varied in the range of 310 to 160 nm with increasing the carbonization temperature. These results could be explained that the graphitic region of carbon webs was formed after carbonization at high temperatures. And the amorphous structure of polymeric fiber webs was significantly changed to the graphitic crystalline, resulting in shrinking the size of fiber diameters.