• 제목/요약/키워드: Basic and Analytical Science

검색결과 345건 처리시간 0.024초

Development of Multi-sample Loading Device for TEM Characterization of Hydroxyapatite Nanopowder

  • Lee, Jong-Moon;Kim, Jung-Kyun;Jeong, Jong-Man;Kim, Jin-Gyu;Lee, Eunji;Kim, Youn-Joong
    • Bulletin of the Korean Chemical Society
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    • 제34권3호
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    • pp.788-792
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    • 2013
  • A shortcoming of using transmission electron microscopy (TEM) for structural analysis via electron diffraction is the relatively large error of the measurements as compared to X-ray diffraction. To reduce these errors, various internal standard methods from earlier studies have been widely used. We developed a new device to facilitate the application of internal standard methods in preparation of TEM grids used for nanopowder analysis. Through the application of a partial mask on the TEM grid, both the internal standards and the research materials can be loaded on the same grid. Through this process, we conducted a TEM analysis that compared synthetic hydroxyapatite (HAp) nanopowder to bone apatite from a bovine femur. We determined that the accuracy of the d-spacing measurements of the HAp and bone powders could be improved to better than 1% after statistical treatments of the experimental data. By applying a quarter mask, we loaded four different nanoparticles on a single TEM grid, with one section designated for the internal standard.

관절성 루머티스 환자의 머리카락 중 아연의 분석 (Determination of Zinc in the Scalp Hair of the Reumatoid Arthritis Patients)

  • 김정애;박상민;이원;최범석
    • 분석과학
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    • 제8권1호
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    • pp.101-105
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    • 1995
  • The concentration of zinc of the Reumatoid Arthritis patients has been determined by ICP-AES, and the analytical results are discussed. It is observed that the zinc concentration is largely affected by the length of scalp hair. The concentrations of zinc in the distal end are much higher than that of the proximal end.

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Coumarin 유도체들의 전기화학적 환원과 형광성의 증강 (Enhancement of Fluorescent Properties and Electrochemical Reduction of Coumarin Derivatives)

  • 천현자;김성현;정은주;이혜숙;김일광
    • 분석과학
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    • 제18권1호
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    • pp.89-95
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    • 2005
  • Studies on the electrochemical reduction of 7-acetoxy-4-bromomethyl-coumarin (ABMC), 7-acetoxymethyl coumarin (AMC), and coumarin in 0.1 M tetraethyl ammonium perchlorate acetonitrile solution were carried out with direct current, differential pulse polarography, cyclic voltammetry, and controlled potential coulometry. The electrochemical reduction of ABMC was proceeded through three irreversible steps coupled with the chemical reactions. The solution color was changed to yellow when the carbonyl group was reduced during second step and the color change was independent with bromo group of ABMC. Fluorescent intensity was highest when the electrochemical reduction was controlled at near the overpotential of supporting electrolyte (-2.3 volts).

적외선열화상카메라의 응답 및 노이즈 특성 평가 (Responsivity and Noise Evaluation of Infrared Thermal Imaging Camera)

  • 김동익;김기석;김건희;장기수
    • 비파괴검사학회지
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    • 제33권4호
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    • pp.342-348
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    • 2013
  • 본 논문에서는 비접촉 비파괴검사에 사용되는 적외선열화상카메라의 응답 및 노이즈 특성을 평가할 수 있는 방법을 제시하고 있으며 차동모드흑체의 적외선 표적과 그 주변의 온도차 ${\Delta}$T를 이용하여 상용 적외선열화상카메라의 신호전달함수 및 온도분해능을 구하고 그 결과를 카메라 사양과 비교함으로써 본 평가 방법의 적합성을 검증하였다. 또한 비균일성 보정의 적용 유무로부터 나타나는 온도분해능의 차이 0.01 K을 통하여 적외선열화상카메라의 성능평가에 있어서 비균일성 보정이 필수적인 과정임을 확인하였다.

Comparison of USEPA Digestion Methods for Trace Metal Analysis Using SRM

  • Shin, Mi-Young;Yoon, Hyeon;Kim, Youn-Tae;Yoon, Cheol-Ho;Woo, Nam-Chil
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.223-226
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    • 2004
  • The importance of a proper sample preparation and analysis technique has getting attention due to the complicity of toxic elements of interest from environmental samples depend on analytical purposes. It is critical to use proper analytical method to evaluate trace elements concentration in many environmental samples especially for making remediation decisions. Therefore, it is critical to apply a proper sampling and analytical method such as EPA publication SW-846 (Test Methods for Evaluating Solid Waste, Physical/chemical Methods). The objective of this study was to compare the USEPA Methods 3050B, modified 3050B, 305 la, and KBSI method (modified EPA 3052 Method) in term of recovery rate of metals. The NIST SRM (Montana soil) was used to compare the extraction and digestion efficiency. After sample has been collected the analysis were achieved by ICP-MS (Elan 6100, Perkin Elmer) as well as ICP-AES (Ultima 2C, JY) for trace elements and major elements.

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먹는샘물 중의 건강과 맛에 영향을 미치는 화학성분의 분석 (Determination of the Chemical Constituents to Affect the Health and Taste in Bottled Drinking Waters)

  • 이남례;김영만;최범석
    • 분석과학
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    • 제10권6호
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    • pp.459-467
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    • 1997
  • Due to the growing demand for bottled mineral waters, a study was undertaken to determine the quality of the twenty six brands of domestic and imported drinking waters. The quality of water was evaluated by analyzing the twenty four elements including minerals, essential and/or toxic trace elements, and the analytical items to affect the taste of water. The contribution of drinking water to the mineral nutrition of human was calculated in order to investigate the health effect of drinking water. The taste of water was evaluated in terms of minerals, anions, TDS, alkalinity, hardness and pH.

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Studies on The Elution Behavior of Ni(II)-${\alpha}$-isonitroso-${\beta}$-diketone Imine Chelates in Reversed-Phase Liquid Chromatography

  • Lee, Won;Kim, In-Whan;Kim, Mi-Kyoung;Kim, Yong-Jun;Jung, Hae-Rim;No, Kyoung-Tai;Kim, Su-Yeon
    • 분석과학
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    • 제8권4호
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    • pp.519-527
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    • 1995
  • The retention mechanism of Ni(II)-${\alpha}$-isonitroso-${\beta}$-diketone imine chelates in reversed-phase HPLC has been studied by examining the effect of temperature, mobile phase composition in acetonitrile-water mixture, and molecular structure on retention. The empirical retention equation was investigated to evaluate the properties of S (hydrophilic index). The value of the S index of the Ni(II) chelates decrease with the increasing column temperature and a linear relationship between S and log $k{_w}^{\prime}$ has been found. The results showed that the S index is influenced by the interaction between Ni(II) chelates and mobile phase. Molecular properties, van der Waals molar volume, polarizability and dipole moment, of the Ni(II) chelates were calculated by Cerius 2 program and the calculations were performed at Universal Force Field (UFF) model. The S value and log $k{_w}^{\prime}$ increase with decreasing the dipole moment of Ni(II) chelates.

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Positron emission tomography and magnetic resonance imaging

  • Yim, Min Su;Ryu, Eun Kyoung
    • 대한방사성의약품학회지
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    • 제2권1호
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    • pp.3-8
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    • 2016
  • Molecular imaging technologies have been used to provide a new pathway for therapies and diagnosis of human disease. Especially, imaging probes have been much development in the molecular imaging field. Combining imaging probes for positron emission tomography (PET) and magnetic resonance imaging (MRI) have suggested the potential of multiple methods in living body. This review discusses the cancer or lymph node-targeting probes that are suitable for PET/MRI based diagnosis.

The targeting peptides for tumor receptor imaging

  • Yim, Min Su;Ryu, Eun Kyoung
    • 대한방사성의약품학회지
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    • 제2권2호
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    • pp.63-68
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    • 2016
  • Peptides have been developed for in vivo imaging probes against to the specific biomarker in the biological process of living systems. Peptide based imaging probes have been applied to identify and detect their active sites using imaging modalities, such as PET, SPECT and MRI. Especially, tumor receptor imaging with the peptides has been widely used to specific tumor detection. This review discusses the targeting peptides that have been successfully characterized for tumor diagnosis by receptor imaging.