• 제목/요약/키워드: morphological properties

검색결과 1,056건 처리시간 0.034초

Effect of Multi-walled Carbon Nanotube Dispersion on the Electrical, Morphological and Rheological Properties of Polycarbonate/Multi-walled Carbon Nanotube Composites

  • Han, Mi-Sun;Lee, Yun-Kyun;Kim, Woo-Nyon;Lee, Heon-Sang;Joo, Jin-Soo;Park, Min;Lee, Hyun-Jung;Park, Chong-Rae
    • Macromolecular Research
    • /
    • 제17권11호
    • /
    • pp.863-869
    • /
    • 2009
  • The effect of a multiwalled carbon nanotube (MWCNT) dispersion on the electrical, morphological and rheological properties of polycarbonate (PC)/MWCNT composites was investigated, with and without pretreating the MWCNTs with hydrogen peroxide oxidation and lyophilization. The resulting PC/treated MWCNT composites showed higher electrical conductivity than the PC/untreated MWCNT composites. The morphological behavior indicated the treated composites to have greater dispersion of MWCNTs in the PC matrix. In addition, the electromagnetic interference shielding efficiency (EMI SE) of the treated composites was higher than that of the untreated ones. Rheological studies of the composites showed that the complex viscosity of the treated composites was higher than the untreated ones due to increased dispersion of the MWCNTs in the PC matrix, which is consistent with the electrical conductivity, EMI SE and morphological studies of the treated composites. The latter results suggested that the increased electrical conductivity and EMI SE of the treated composites were mainly due to the increased dispersion of MWCNTs in the PC matrix.

Depth edge detection by image-based smoothing and morphological operations

  • Abid Hasan, Syed Mohammad;Ko, Kwanghee
    • Journal of Computational Design and Engineering
    • /
    • 제3권3호
    • /
    • pp.191-197
    • /
    • 2016
  • Since 3D measurement technologies have been widely used in manufacturing industries edge detection in a depth image plays an important role in computer vision applications. In this paper, we have proposed an edge detection process in a depth image based on the image based smoothing and morphological operations. In this method we have used the principle of Median filtering, which has a renowned feature for edge preservation properties. The edge detection was done based on Canny Edge detection principle and was improvised with morphological operations, which are represented as combinations of erosion and dilation. Later, we compared our results with some existing methods and exhibited that this method produced better results. However, this method works in multiframe applications with effective framerates. Thus this technique will aid to detect edges robustly from depth images and contribute to promote applications in depth images such as object detection, object segmentation, etc.

택사의 생약학적 연구 (Pharmacognostical Studies on Alisma Plants)

  • 도정애
    • 생약학회지
    • /
    • 제26권4호
    • /
    • pp.411-418
    • /
    • 1995
  • In order to clarify the originality of several Alisma Rhizomes, we investigated the differences of their morphological, anatomical and physiochemical characteristics. Morphological observation shows the variability of Alisma shape and quality. The diversities in morphological shapes and qualities of tuber were observed among different origins. Chinese product looked like corm shape, but korean's irregular shape. The microscopic observation of korean Alisma revealed the presence of irregular vascular bundle which was scattered transversely and longitudinaly, which was different from that of the rhizome. This facts suggest that the portion of crude drug in Alisma should be the corm rather than the rhizome. In the physicochemical differences, chinese Alisma contains larger amount of mineral elements such as K, Na and Ca than korean Alisma. On the contrary, protein contents in lyophilized powder of aqueous extracts in korean Alisma rhizome was significantly higher than chinese Alisma rhizome. The leaves and stems contained larger amount of Ca and Na than tuber, and may be used as the osmotic diuretics for chinese traditional medicine.

  • PDF

Unipolar pulse를 이용하여 형성된 Al6061 합금 표면의 MAO 코팅의 표면 구조에 대한 연구 (Surface Morphological Properties of Micro-arc Oxidation Coating on Al6061 Alloys using Unipolar Pulse)

  • 김남열;박승호;박기용;최진섭
    • 한국표면공학회지
    • /
    • 제50권5호
    • /
    • pp.421-426
    • /
    • 2017
  • Herein, we investigated surface morphological characteristics of anodic films on Al6061 alloy prepared by unipolar pulsed Micro-arc oxidation (MAO) in a mixed solution of $Na_2SiO_3$ + KOH. The number and size of pores as well as craters on anodic alumina surface were studied as a function of different voltages, duty cycles and applied anodic current densities. The morphological characteristics of all samples were investigated by scanning electron microscopy, conforming that the most uniform surface morphology of MAO films on Al1050 alloy was obtained at high applied current density with low duty cycle.

Electro-optic Properties of Reflective HPDLC with Fluorinated Polymer Matrices

  • Woo, Ju-Yeon;Kim, Eun-Hee;Kim, Byung-Kyu
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
    • /
    • pp.516-519
    • /
    • 2003
  • We modified the molecular structure of urethane acrylate oligomer by varying raw materials. Also fluorination of the host polymer matrices has been found to influence the morphological and the electrooptical properties of the resulting HPDLC grating. The incorporation of fluorinated monomers in HPDLC formulation enhance the LC phase separation and improved elctro-optical properties.

  • PDF

산소 유량비 변화에 따른 AlN 박막의 구조, 표면 및 광학적 특성 (Structural, Morphological, and Optical Properties of AlN Thin Films Subjected to Oxygen Flow Ratio)

  • 조신호;김문환
    • 한국진공학회지
    • /
    • 제19권4호
    • /
    • pp.287-292
    • /
    • 2010
  • 산소 유량비 변화에 따른 라디오파 반응성 마그네트론 스퍼터링 방법으로 성장된 AlN 박막의 구조, 표면 및 광학적 특성을 조사하였다. AlN 박막은 기판 온도 $300^{\circ}C$에서 성장되었으며, 반응성 가스로 질소와 산소 가스를 사용하였다. 산소 유량비는 공급되는 질소와 산소 혼합 가스양에 대한 산소의 유량비로 선택하여 0%, 10%, 15%, 20%, 25%, 30%로 제어하였다. 성장된 AlN 박막의 구조, 표면과 광학적 특성은 각각 X-선 회절장치, 전자주사현미경과 자외선-가시광 분광기를 사용하여 조사하였다. 산소 유량비 10%로 증착된 AlN 박막은 350~1,100 nm 파장 영역에서 평균 91.3%의 투과율과 4.30 eV의 광학 밴드갭 에너지를 나타내었다. 실험 결과는 산소 유량비를 변화시킴으로써 AlN 박막을 선택적으로 성장시킬 수 있음을 제시한다.

폴리유산/폴리부틸렌숙시네이트 블랜드의 가공 및 기계적, 열적, 형태학적 특성 (Processing and Mechanical, Thermal and Morphological Properties of Poly(lactic acid)/Poly(butylene succinate) Blends)

  • 김대근;조동환
    • 접착 및 계면
    • /
    • 제15권1호
    • /
    • pp.14-21
    • /
    • 2014
  • 본 연구에서는 이축압출기와 사출기를 사용하여 폴리유산(PLA)와 폴리부틸렌숙시네이트(PBS) 수지의 함량비를 달리하여 PLA/PBS 블랜드를 제조하고, 그들의 기계적, 열적 특성 및 모폴로지를 조사하였다. PLA/PBS 블랜드의 굴곡강도, 굴곡탄성률, 인장강도 및 인장탄성률과 같은 기계적 특성, 그리고 용융거동, 동역학적 열특성 및 열안정성과 같은 열적 특성이 PLA와 PBS 함량비에 크게 의존하였다. 그러나 PLA/PBS 블랜드의 열변형온도는 PLA 또는 PBS 함량 변화에 크게 영향을 받지 않았다. 또한 PLA/PBS 블랜드의 파단면은 PBS 함량이 증가함에 따라 brittle 양상으로부터 ductile 양상으로 변화되었다.

Study of microstructure of carbon-based materials in plasma wind tunnel testing

  • Kang, Bo-Ram;Lim, Hyeon-Mi;Oh, Phil-Yong;Hong, Bong Guen
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
    • /
    • pp.200.2-200.2
    • /
    • 2016
  • Carbon-based materials have been known as ablative material and have been used for thermal protection systems. Ablation is an erosive phenomenon that results in thermochemical and thermomechanical changes on materials. Ablation resistance is one of the key properties that determines performance and life-time of the thermal protection material under ablative conditions. In this study, ablation properties of graphite, 3-dimensional (C/C) composites (needle-punched type and rod type) were investigated byusing a plasma wind tunnel which produce a supersonic plasma flow from a segmented arc heater with the power level of 0.4 MW. The mass losses and surface roughness changes which contain main result of the ablation are measured. A morphological analysis ofthe carbon-based materials, before and after the ablation test, are performed through field emission scanning electron microscopy (FE-SEM) and non-contact 3D surface measuring system. Electronic balance and a portable surface roughness tester were used for evaluation of the recession and mass loss of the test samples.

  • PDF

친환경 난연제와 탈크를 첨가한 목재·플라스틱 복합재의 기계적, 열적, 형태학적 및 수분흡수 특성에 관한 연구 (A Study on the Mechanical, Thermal, Morphological, and Water Absorption Properties of Wood Plastic Composites (WPCs) Filled with Talc and Environmentally-Friendly Flame Retardants)

  • 이단비;김범준
    • 한국가구학회지
    • /
    • 제27권2호
    • /
    • pp.137-144
    • /
    • 2016
  • Wood plastic composite (WPC) is a green composite made of wood flour and thermoplastics to provide better performance by removing the defects of both wood and plastics. However, relatively low thermal stability and poor fire resistance of wood and plastics included in WPC have been still issues in using WPC as a building material for interior applications. This study investigated the effect of environmentally-friendly flame retardants (EFFRs) on the mechanical, thermal, morphological, and water absorption properties of wood flour (WF)/talc/polypropylene (PP) composites in comparison with neat PP. The whole EFFRs-filled WF/talc/PP composites showed higher values in flexural strength, flexural modulus, and impact strength compared to neat PP. In thermal properties, aluminum hydroxide (AH)-filled composite showed a $36^{\circ}C$ reduction in maximum thermal decomposition temperature ($T_{max}$) compared to neat PP, but magnesium hydroxide (MH) played an important role in improving thermal stability of filled composite by showing the highest $T_{max}$. From this research, it can be said that MH has potentials in reinforcing PP-based WPCs with improvement of thermal stability.