• 제목/요약/키워드: nanometer

검색결과 595건 처리시간 0.022초

Effects of Nanometer Sized Silver Materials on Biological Toxicity During Zebrafish Embryogenesis

  • Yeo, Min-Kyeong;Kang, Mi-Sook
    • Bulletin of the Korean Chemical Society
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    • 제29권6호
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    • pp.1179-1184
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    • 2008
  • Commercial nanometer sized silver is widely used for its antibacterial effect; however, nanoparticles may also have ecotoxicological effects after being discharged into water. Nanometer sized silver can flow into aquatic environments, where it can exert a variety of physiologically effects in living organisms, including fish. The present study aimed to investigate the effect of nanometer sized silver on the development of zebrafish embryos, analyze the properties of commercial nanometer sized silver and define the toxicity relationship between embryogenesis and hatched flies. The commercial nanometer sized silver was analyzed in the $Ag^+$ ion form. The hatch rate decreased in the nano-silver exposed groups (10 and 20 ppt); furthermore, the hatched flies had an abnormal notochord, weak heart beat, damaged eyes and curved tail. The expression of the Sel N1 gene decreased in the nano-silver exposed groups, and the catalase activities of the exposed groups increased relative to those in the control group. Therefore, the $Ag^+$ ions in commercial nanometer sized silver could accumulate in aquatic environments and seriously damage the development of zebrafish embryos.

나노미터 규격의 친수성 박막 패터닝을 이용한 선택적 폴리스티렌 입자 배열 (Selective Array of Polystyrene Beads by Using Nanometer-Scaled Hydrophilic Thin Film Patterning)

  • 강정화;김경섭;김남훈;노용한
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.103-104
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    • 2007
  • Nanometer-scaled polymer beads, such as polystyrene beads, were used as nanometer fabrication materials due to their some advantages such as self-assembled monolayer, nanometer scaled size and excellent compatibility with silicon based devices. Thus, the investigation on these properties of polymer beads was required. It is difficult to control the array of polystyrene beads on silicon substrate. In this study, we investigated the condition of selective array of polystyrene beads on nanometer-scaled hydrophilic surface which was obtained by APS coating. A tilting method was used to array the polystyrene beads selectively on the substrate. The polystyrene beads could be arrayed selectively by this method. From these results, we verified that there are possibilities to fabricate unique tools for the nanometer-scaled electrical devices.

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나노미터 패턴 회절격자 도광판의 광특성 (Optical Characteristics of LGP with Nanometer-patterned Grating)

  • 홍진수;김창교;이병욱;이명래
    • 제어로봇시스템학회논문지
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    • 제14권4호
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    • pp.353-360
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    • 2008
  • The LGP with nanometer structures resulted in enhancement of optical efficiency. Its fundamental mechanism is to recycle the polarized light via one round-trip through QWP(Quarter-Wave Plate) but the maximum efficiency to reach with this method is limited up to 2. To get the larger efficiency than this limited one a LGP with nanometer-patterned grating is suggested. For its optimum design the computer simulation is performed and suggests a grating that the spatial frequency between adjacent patterns is 500nm, its height 250nm, duty cycle 50%, and its cross section is rectangular. On the basis of simulation results the LGP with nanometer-patterned grating is fabricated and its optical properties such as angular intensity distribution and CIE color coordinates are characterized. The angles of transmitted light are nearly the same as the results expected from the generalized Snell's law. Thus the Mathematica code, developed in this experiment, will be applied to designing the optimized LGP. The LGP with nanometer-patterened grating shows the enhancement of transmitted intensity distribution up to 4.9 times.

복합 나노미터 패턴 도광판의 광특성 (Optical Characteristics of the LGP with Nanometer-patterned Sizes on Its Both Surfaces)

  • 홍진수;김창교;이병욱;김경래
    • 제어로봇시스템학회논문지
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    • 제14권6호
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    • pp.530-534
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    • 2008
  • The LGP with nanometer structures resulted in enhancement of optical efficiency. Its fundamental mechanism is to recycle the polarized light via one round-trip through QWP(Quarter-wave Plate) but the maximum efficiency to reach with this method is limited up to 2. To get the larger efficiency than this a LGP with 1D PC(one-dimensional photonic crystal) nanometer-patterned on its top and bottom surfaces is suggested. For its optimum design the computer simulation is performed and suggests a grating that the spatial frequency between adjacent patterns is 500nm, its height 250nm, duty cycle 50%, and its cross section is rectangular. The angles of transmitted light are nearly the same as the results expected from the generalized Snell's law. Thus the Mathematica code, developed in this experiment, will be applied to designing the optimized LGP. The LGP with nanometer-patterened 1D PC LGP on its both surfaces shows the enhancement of transmitted intensity distribution up to 5.7 times.

Zebrafish 발생기에서 $TiO_2(P-25)$ 나노 입자의 생물 독성 (Bio-toxicity of Titanium Dioxide Nano Particles (P-25) in Zebrafish Development Stage)

  • 여민경;조윤희
    • Environmental Analysis Health and Toxicology
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    • 제22권3호
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    • pp.189-196
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    • 2007
  • [ $TiO_2$ ] is widely used because it is non-toxic. Recently, however, nanometer size $TiO_2$ particles (P-25) have been produced and used to increase the photo catalysis efficiency. Nanometer-sized $TiO_2$ is efficient, but due to its small size ($20{\sim}30\;nm$), it can flow into ecosystems and into cells. Thus, it may affect human health. Additionally, $TiO_2$ can produce a second contaminant, OH-radical, which is a health risk for all living organisms during photo degradation reaction. Hence, when nanometer-sized $TiO_2$ flows into natural streams and attaches to living organisms, it will create health risks. We investigated the biological toxicity of this condition in zebrafish embryos. We observed abnormal morphology, hatching rate, and measured the catalase activity to determine anti-oxidation at 100 post fertilization hours. Zebrafish were somewhat affected by $TiO_2$ nanometer sized particles under UV-A (a condition similar to sunlight). Powdered $TiO_2$ is toxic to the zebrafish fly. Even without light, $TiO_2$ particles attached to embryos and flies, having an effect on both.

반도체 소재의 나노미터 스케일의 변형거동 해석 (Deformation pathway of semiconductor materials in nanometer scale)

  • 김동언;오수익
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.518-520
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    • 2007
  • Since all essential property of semiconductor materials are structure-sensitive, the understanding of the deformation mechanism and the deformed structure which can be formed in the nanometer-scale devices is very crucial. To investigate the deformation mechanism and the corresponding structures, nanometer-scale contact loading simulations are carried out using molecular dynamics in silicon and gallium-arsenide.

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정밀 스캐너를 이용한 간섭 현미경의 가로방향 분해능 향상 (Improved Lateral Resolution of Interferometric Microscope Using Precision Scanner)

  • 박성림;박도민;류재욱;권대갑
    • 한국정밀공학회지
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    • 제15권6호
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    • pp.116-123
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    • 1998
  • An interferometric microscope with an improved lateral resolution is presented. The nanometer resolution XY stage is integrated into standard temporal phase shifting interferometer. The nanometer resolution XY stage is used to position specimen in subpixel of CCD detector, therefore CCD detector's sampling is improved. Two scanning algorithms and those simulation results are also presented. The simulation results show that scanning algorithms improve CCD detector's sampling significantly, and interferometeric microscope's lateral resolution is improved also.

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