• 제목/요약/키워드: Nano-structures

검색결과 939건 처리시간 0.031초

마이크로/나노 구조를 갖는 초발수성 표면의 제작 및 분사 액적의 충돌 특성 연구 (Fabrication of a Micro/Nano-scaled Super-water-repellent Surface and Its Impact Behaviors of a Shooting Water Droplet)

  • 김형모;이상민;이찬;김무환;김준원
    • 한국정밀공학회지
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    • 제29권9호
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    • pp.1020-1025
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    • 2012
  • In this study, we fabricated the superhydrophobic and super-water-repellent surface with the micro/nano scale structures using simple conventional silicon wet-etching technique and the black silicon method by deep reactive ion etching. These fabrication methods are simple but very effective. Also we reported the droplet impact experimental results on the micro/nano-scaled surface. There are two representative impact behaviors as "rebound" and "fragmentation". We found the transition Weber number between "rebound" and "fragmentation" statements, experimentally. Additionally, we concerned about the dimensionless spreading diameters for our super-water-repellent surface. The novel characterization method was introduced for analysis including the "fragmentation" region. As a result, our super-water-repellent surface with the micro/nano-scaled structures shows the different impact behaviors compared with a reference smooth surface, by some meaningful experiments.

Utilizing advanced nano structures to foster ideological education, student engagement, and critical thinking

  • Binbin Zhang;Yong Zhang;Yun Liu;Amir Mohammad Zoghi;T.T. Murmy
    • Advances in nano research
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    • 제17권2호
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    • pp.149-155
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    • 2024
  • It is argued that advanced nanostructures must be integrated into ideological teaching to provide avenues for enhanced student engagement in active learning, with the ultimate goal of creating critical thinking across disciplines. In this regard, educational strategies that correspondingly address the unique structures and applications of the concept could be considered for further study, which would avail students the opportunity for interactive involvement in the educational process. This paper reflects on the potential of nano-enhanced education tools, such as nanosensors and nano-based interactive displays, in providing dynamic and responsive educational environments. It then proceeds to examine exactly how present students-using these technologies, also in the near future-can be equipped to engage with multiple ideas and perspectives to use in application. According to the findings presented, the use of advanced nanostructures in education will enhance effectiveness in methodologies of teaching and learning while preparing students for their future challenges by providing them with skills to navigate and analyze complex ideological landscapes. It is succeeded by the knowledge integration metric, which moved from an initial 61% to 87%, thereby growing by 42.62%.

산화아연을 이용한 나노격자 구조의 표면 플라즈몬 공명 (Surface Plasmon Resonance Based on ZnO Nano-grating Structure)

  • 김두근;김선훈;기현철;김회종;오금윤;최영완
    • 전기학회논문지
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    • 제59권5호
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    • pp.922-926
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    • 2010
  • We have investigated the grating coupled surface plasmon resonance (GC-SPR) sensors using ZnO nano-grating structures to enhance the sensitivity of an SPR sensor. The GC-SPR sensors were analyzed using the finite-difference time-domain method. The optimum resonance angles of 49 degrees are obtained in the 150 nm wide grating structure with a period of 300 nm for the ZnO thickness of 30 nm. Then, the ZnO nano-grating patterns were fabricated by using laser interference lithography. The measured resonance angle of nano-grating patterns was around 49 degrees. Here, an enhanced evanescent field is obtained due to the surface plasmon on the edge of the bandgap when the ZnO grating structures are used to excite the surface palsmon.

아질산칼슘과 탄산나노버블수를 사용한 모르타르의 성능 평가 (The Performance Evaluation of Mortar Using Calcium Nitrite and CO2 Nano-Bubble Water)

  • 김호진;김진성;최형길
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 가을 학술논문 발표대회
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    • pp.145-146
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    • 2020
  • This study investigated the performance evaluation of polymer cement mortar for repairing concrete structures using calcium nitrite(Ca(NO2)2) and CO2 nano-bubble mixing water to develop section-restoration methods for the repair and reinforcement of cracks. The evaluation items were strength and microstructure analysis at 28 days of age according to the change in the amount of calcium nitrite and the use of CO2 nano-bubble water. As a result of the experiment, it was confirmed that the performance of polymer cement mortar for repairing concrete structures was improved by the generation of nitrite-based hydration products when calcium nitrite and CO2 nano-bubble water were used.

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Molecular Orientation of Intercalants Stabilized in the Interlayer Space of Layered Ceramics: 1-D Electron Density Simulation

  • Yang, Jae-Hun;Pei, Yi-Rong;Piao, Huiyan;Vinu, Ajayan;Choy, Jin-Ho
    • 한국세라믹학회지
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    • 제53권4호
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    • pp.417-428
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    • 2016
  • In this review, an attempt is made to calculate one-dimensional (1-D) electron density profiles from experimentally determined (00l) XRD intensities and possible structural models as well in an effort to understand the collective intracrystalline structures of intercalant molecules of two-dimensional (2-D) nanohybrids with heterostructures. 2-D ceramics, including layered metal oxides and clays, have received much attention due to their potential applicability as catalysts, electrodes, stabilizing agents, and drug delivery systems. 2-D nanohybrids based on such layered ceramics with various heterostructures have been realized through intercalation reactions. In general, the physico-chemical properties of such 2-D nanohybrids are strongly correlated with their heterostructures, but it is not easy to solve the crystal structures due to their low crystallinity and high anisotropic nature. However, the powder X-ray diffraction (XRD) analysis method is thought to be the most powerful means of understanding the interlayer structures of intercalant molecules. If a proper number of well-developed (00l) XRD peaks are available for such 2-D nanohybrids, the 1-D electron density along the crystallographic c-axis can be calculated via a Fourier transform analysis to obtain structural information about the orientations and arrangements of guest species in the interlayer space.

Fabrication of ZnO Nanostructures with Various Growth Conditions by Vapor Phase Transport

  • Kim, So-A-Ram;Nam, Gi-Woong;Kim, Min-Su;Yim, Kwang-Gug;Kim, Do-Yeob; Leem, Jae-Youn
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.250-250
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    • 2011
  • Zinc oxide (ZnO) structures have great potential in many applications. Currently, the most commonly used method to grow ZnO nanostructres are the vapor transport method (VPT). The morphology of the ZnO structures largely related to the growth conditions, including growth temperature, distance between the substrate and source, and gas ambient. Previously ZnO nanosturecutres with high crystallinity were obtained at the growth temperature of 800$^{\circ}C$, in the argon and oxygen gas ambient. In this study, we report the properties of the ZnO nanostructures, which were synthesized on Au-catalyzed Si substrate by VPT, using a mixture of ZnO and graphite powders as source material under the different condition, including gas ratio of argon/oxygen and distance between substrate and source at the growth temperature of 800$^{\circ}C$. The structural and optical properties of the ZnO nanostructures were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and photoluminescence (PL).

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MOVPE에 의한 GaN 피라미드 꼭지점 위의 반극성 나노/마이크로 크기의 GaN 성장 (Fabrication of semi-polar nano- and micro-scale GaN structures on the vertex of hexagonal GaN pyramids by MOVPE)

  • 조동완;옥진은;윤위일;전헌수;이강석;정세교;배선민;안형수;양민;이영철
    • 한국결정성장학회지
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    • 제21권3호
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    • pp.114-118
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    • 2011
  • 본 논문에서는 육각형 GaN 피라미드의 꼭지점 부분에만 나노 혹은 마이크로 크기의 GaN 구조를 선택적으로 성장시킬 수 있는 결정 성장 방볍에 대하여 연구하였다. 최적화된 포토리소그라피 공정을 이용하여 육각형 GaN 피라미드 구조의 꼭지점 부분의 $SiO_2$ 마스크 영역만을 제거할 수 있었으며, 이렇게 하여 노출된 육각형 GaN 피라미드의 꼭지점 부분에만 metal organic vapor phase epitaxy(MOVPE) 결정 성장방법을 사용하여 나노 및 마이크로 크기의 GaN 구조를 선택적으로 성장하였다. GaN 피라미드 꼭지점 부근에 형성된 나노 및 마이크로 G값J 구조는 semi-polar {1-101} 결정면으로 둘러싸인 육각 피라미드 형상을 하고 있으며 그들의 크기는 성장 시간에 의해 쉽게 조절할 수 있음을 확인하였다. TEM 관측 결과, 측면 방향으로 진행하는 관통전위들이 $SiO_2$ 마스크에 의해 효율적으로 차단되어 나노 및 마이크로 GaN 구조에서는 전위 밀도가 감소하는 것을 확인할 수 있었으나 $SiO_2$ 마스크의 끝부분의 매끄럽지 못한 부분에 의해 적층 결함이 발생함을 확인하였다.