• 제목/요약/키워드: morphology formation

검색결과 1,229건 처리시간 0.027초

Morphology of middle cerebral artery using computed tomography angiographic study in a tertiary care hospital

  • Urvi Sharma;Suman Verma;Subathra Adithan
    • Anatomy and Cell Biology
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    • 제56권3호
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    • pp.360-366
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    • 2023
  • Increased tortuosity of vessel is associated with high incidence of plaque formation leading to atherosclerosis. Surgical procedures are done after analyzing morphology of middle cerebral artery (MCA). However, literature describing MCA morphology using computed tomography angiography (CTA) is limited, so this study was planned to determine its incidence in Indian population. Datasets of CTA from 289 patients (180 males and 109 females), average age: 49.29±16.16 years (range: 11 to 85 years), from a tertiary care hospital were systematically reviewed for morphology of MCA. Cases involving aneurysms and infarcts were excluded. Four shapes of MCA were recognized: straight, U, inverted U, and S-shaped. MCA was straight in 44% (254/578), U-shaped in 37% (215/578), S shaped in 15% (89/578) and inverted U-shaped in 3% (20/578) cases. In males, MCA was straight in 46% (166/360), U-shaped in 37% (134/360), S-shaped in 16% (58/360) and inverted U-shaped in 4% (14/360) cases. In females, MCA was straight in 42% cases (92/218), U-shaped in 37% (81/218), S-shaped in 17% (36/218) and inverted U-shaped in 4% (9/218). On comparing shape with various age groups using chi square test, U shaped (P≤0.001) and S-shaped (P=0.003) MCA were found to be statistically significant. The incidence of straight shape was higher in advanced age group (>60 years). Knowledge of MCA shape will be useful for clinicians and surgeons in successful endovascular recanalization. Also, this data would help surgeons during neurointerventional procedures.

Preparation of Silica Hollow Composite Particles

  • Lee, Dong Hoon;Lee, Chang Hyun
    • Bulletin of the Korean Chemical Society
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    • 제35권11호
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    • pp.3303-3306
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    • 2014
  • A facile and effective approach has been developed to prepare hybrid hollow microspheres, via consecutive processes of pickering mini-emulsion polymerization for core-shell formation, and calcination of the sacrificial core. The resulting hollow composite particles have mono-layered shells. The morphology and size characteristics of synthesized composite particles were investigated, using dynamic light scattering (DLS) and scanning electron microscopy (SEM) measurements.

Formation of Barrier ribs for PDP by Water Jet Etching of Green Tape

  • Cho, Yu-Jeong;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.784-787
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    • 2003
  • In this study, water jet etching of aqueous green tape was attempted for processing barrier rib of plasma display panel. This process combines 1) chemical etching between water and aqueous based binder in the tape and 2) mechanical erosion by water jet. Effects of etching parameters such as pressure, temperature and aqueous binder content on the morphology of barrier ribs formed were investigated. The results demonstrated a possibility of processing barrier ribs by water jet etching.

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Application of the electroless plating method to the fabrication of metallic bus electrodes of PDP

  • Oh, Young-Joo;Jeung, Won-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.829-831
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    • 2003
  • In the present study, the electroless plating method was applied instead of the sputtering as a formation method of metallic bus electrodes. No additional blackening step is needed in this method since this process provides a metallic seed layer with black color by a single step. The parameters which affects color and morphology of the metallic seed layer in the electroless plating solution were investigated

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다결정 실리콘의 화학증착에 대한 연구 (A Study on Chemical Vapor Deposition of Polycrystalline Silicon.)

  • 소명기
    • 산업기술연구
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    • 제2권
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    • pp.13-19
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    • 1982
  • Polycrystalline silicon layers have been deposited by a chemical vapor deposition technique using $SiCl_4$, $H_2$ gas mixture on single crystal silicon substrates. In this work, the effects of depostion temperature and total flow rate on the deposition rate of polycrystalline silicon are investigated. From the experimental results it was found that the formation reaction of polycrystalline silicon was limited by surface reaction and mass transfer controlled as the deposition temperature was increased. The morphology of polycrystalline silicon layer changed from a fine structure to a coarse one as the deposition temperature was increased.

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Physico-Chemical Properties of Various Oxide Nanoparticles Synthesized with Electron Beam Irradiation System

  • 신원규
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.437-437
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    • 2014
  • Various oxide particles are synthesized in an ambient condition using an electron beam irradiation system. The formation of oxide particles is confirmed by FT-IR spectra results and the X-ray photoelectron spectrum. It is also shown that the morphology and size of oxide particles are significantly influenced by the type and flowrate of dilution gas. The energy dispersive X-ray (EDX) analysis also confirms that various oxide particles are synthesized.

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SPH Simulations of Barred Galaxies: Evolution of Nuclear Rings

  • ANN H. B.
    • 천문학회지
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    • 제34권4호
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    • pp.261-263
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    • 2001
  • Numerical simulations based on the smoothed particle hydrodynamics (SPH) is performed to investigate the dynamical properties of barred galaxies that have nuclear rings. The nuclear ring morphology depends on the relative strength of bar potentials. Nuclear rings form between the two ILRs and align perpendicular to the bars unless the bar potentials are strong enough to allow the x1 orbits near the ILRs. Shock dissipation plays a critical role in the formation of nuclear rings.

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Experimental and Numerical Study on Anisotropic Phase Separation of Liquid Crystal and Polymer Composites Cell Gap Variation

  • Jin, Min-Young;Bae, Ji-Hong;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.567-570
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    • 2007
  • Cell gap dependence on anisotropic phase separation was studied. The results showed that the morphology of phase separation depended on cell gap and material parameters. With numerical simulation and experiments, the optimal range of cell gap in the formation of polymer layer and liquid crystal was suggested for given material parameters.

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폴리비닐알콜로 제조된 나노복합막 (Nanofiltration Composite Membranes Based on Poly(vinyl alcohol))

  • 오남운;제갈종건;이규호
    • 한국막학회:학술대회논문집
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    • 한국막학회 1998년도 추계 총회 및 학술발표회
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    • pp.106-108
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    • 1998
  • It has been proved by the study on nanofiltration with PVA dense membranes in our laboratory that the PVA is good material for the formation of chemically stable nanofiltration (NF) membranes. However, the PVA NF composite membranes prepared so far have rarely shown flux and rejection high enough for the commerciallyzation. The reasons for them would be the relatively thick thickness and improper crosslinking degree of the PVA active layers of the composite membranes. In this study, PVA composite membranes with improved nanofiltration properties have been prepared and characterized in terms of the morphology and permeation properties.

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양극산화 피막형성에 관한 연구(I) (Anodic Film Formation on Aluminum(I))

  • 한성호
    • 한국표면공학회지
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    • 제21권3호
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    • pp.130-141
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    • 1988
  • 최근에 와서 알루미늄소재의 양극산화피막 형성Mechanism에 관한 연구는 응용분야의 폭넓어지면서 많은 연구가 진행되고 있다. 최신분석 장비의 응용의 폭이 넓어짐으로 해서 연구의 깊이도 점차 증가되고 있는 실정이다. 따라서, 선진국 양극산화피막에 관한 연구는 어디까지 왔는가를 조명하므로 해서 그 응용의 기반을 확고히 하기 위해 본 Review를 연재하고자 한다. 본고에서는 가장 기본적인 연구과제와 양극화산화피막의 Morphology에 관한 내용이다.

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