• Title/Summary/Keyword: Chemical imaging

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Long-term Testing and Analysis of a ScSZ/LaSrCuFe Cell

  • Wackerl, Jurgen;Peck, Dong-Hyun;Markus, Torsten
    • Journal of the Korean Ceramic Society
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    • v.45 no.12
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    • pp.788-795
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    • 2008
  • An electrolyte supported SOFC cell was tested at $800^{\circ}C$ in air for 3600 h with an applied current density of $200\;mA/cm^2$ to examine possible cathode degradation issues. A scandium- stabilized zirconia (ScSZ) with additional manganese doping (ScSZ: Mn) was used as electrolyte. A strontium and copper-doped lanthanum ferrite (LaSrCuFe) and platinum were used as cathode and quasi-anode material, respectively. The DC resistance was logged over the complete testing period. Additionally, impedance spectroscopy was used from time to time to track changes of the cell in-situ. Post-test analysis of the cell using methods like scanning electron microscopy imaging and other electrochemical testing methods allow the identification of different degradation sources. The results indicate a promising combination of electrolyte and cathode material in terms of chemical compatibility and electrical performance.

Fabrication of 64x1 linear array infrared detector using Hg1-xCdxTe (Hg1-xCdxTe를 이용한 64x1 선형 적외선 감지 소자 제작)

  • Kim, Jin-Sang;Suh, Sang-Hee
    • Journal of Sensor Science and Technology
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    • v.18 no.2
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    • pp.135-138
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    • 2009
  • $64{\times}1$ forcal plane infrared detector has been fabricated by using HgCdTe epi layer. HgCdTe was grown on GaAs substrate by using metal organic chemical vapor deposition. This paper describes key developments in the epi layer growth and device fabrication process. The performance of IR imaging system is summarized.

Current Status of Liquid-cell Transmission Electron Microscopy (액상 투과전자현미경 분석기법 소개 및 최신 연구동향)

  • Hong, Jaeyoung;Chun, Dong Won
    • Ceramist
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    • v.22 no.4
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    • pp.417-428
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    • 2019
  • Even though, nanoscale materials of various shapes and compositions have been synthesized in the liquid, their underlying growth and transformation mechanisms are not well understood due to a lack of analytical methods. The advent of liquid cell for transmission electron microscope (TEM) enables the direct imaging of chemical reactions that occur in liquids with nanometer resolution of the electron microscope (EM). Here, the technical development of liquid cell TEM equipment and their applications to the study of nanomaterials analysis in liquid are discussed. Also new findings discovered through liquid cell TEM studies such as nucleation & growth, coalescence process and transformation are discussed.

Analysis of Ceramics Using Scanning Electron Microscopy (주사전자현미경을 활용한 세라믹의 분석)

  • Lee, Sujeong
    • Ceramist
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    • v.22 no.4
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    • pp.368-380
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    • 2019
  • A ceramic is used as a key material in various fields. Accordingly, the use of scanning electron microscopy is increased for the purpose of evaluating the reliability and defects of advanced ceramic materials. The scanning electron microscope is developed to overcome the limitations of optical microscopy and uses accelerated electrons for imaging. Various signals such as SE, BSE and characteristic X-rays provide useful information about the surface microstructure of specimens and, the content and distribution of chemical components. The development of electron guns, such as FEG, and the improved lens system combined with the advanced in-lens detectors and STEM-in-SEM system have expanded the applications of SEM. Automated SEM-EDS analysis also greatly increases the amount of data, enabling more statistically reliable results. In addition, X-ray CT, XRF, and WDS, which are installed in scanning electron microscope, have transformed SEM a more versatile analytical equipment. The performance and specifications of the scanning electron microscope to evaluate ceramics were reviewed and the selection criteria for SEM analysis were described.

Small-molecule probes elucidate global enzyme activity in a proteomic context

  • Lee, Jun-Seok;Yoo, Young-Hwa;Yoon, Chang No
    • BMB Reports
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    • v.47 no.3
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    • pp.149-157
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    • 2014
  • The recent dramatic improvements in high-resolution mass spectrometry (MS) have revolutionized the speed and scope of proteomic studies. Conventional MS-based proteomics methodologies allow global protein profiling based on expression levels. Although these techniques are promising, there are numerous biological activities yet to be unveiled, such as the dynamic regulation of enzyme activity. Chemical proteomics is an emerging field that extends these types proteomic profiling. In particular, activity-based protein profiling (ABPP) utilizes small-molecule probes to monitor enzyme activity directly in living intact subjects. In this mini-review, we summarize the unique roles of smallmolecule probes in proteomics studies and highlight some recent examples in which this principle has been applied.

Clearing and Labeling Techniques for Large-Scale Biological Tissues

  • Seo, Jinyoung;Choe, Minjin;Kim, Sung-Yon
    • Molecules and Cells
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    • v.39 no.6
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    • pp.439-446
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    • 2016
  • Clearing and labeling techniques for large-scale biological tissues enable simultaneous extraction of molecular and structural information with minimal disassembly of the sample, facilitating the integration of molecular, cellular and systems biology across different scales. Recent years have witnessed an explosive increase in the number of such methods and their applications, reflecting heightened interest in organ-wide clearing and labeling across many fields of biology and medicine. In this review, we provide an overview and comparison of existing clearing and labeling techniques and discuss challenges and opportunities in the investigations of large-scale biological systems.

Suggestions for Radiopharmaceutical Drug Development in Korea Focusing on FDA Exploratory IND Guideline (FDA exploratory IND의 기준을 중심으로 본 국내 방사성 의약품 기술개발을 위한 제언)

  • Ryu, Young-Hoon;Choi, Tae-Hyun
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.6
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    • pp.525-529
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    • 2007
  • Regulation for the radiopharmaceuticals should be reasonably different from that of other drugs. Radiopharmaceuticals are always used by compounding based on the doctor's order, have short half life and very low administration dose. Its pharmacological effect is not from its chemical effect but from radiation. The background for exploratory IND (Investigational New Drug) explained by the FDA was to reduce the time and resources expended on candidate products that are unlikely to suceed, new tools are needed to distinguish earlier in the process those candidates that hold promise from those that do not. In this review, basic concept for exploratory IND and RDRC guideline is summarized and various suggestions for improving and expediting procedure for new radiopharmaceutical development would be described.

A Study on Real-Time Corrosion Thickness Measurement Technique of Insulated Pipeline (보온재 부착 파이프라인의 부식두께 측정에 관한 연구)

  • Jang, Ji-Hun;Jo, Gyeong-Sik;Lee, Jong-O;Kim, Gi-Dong
    • 연구논문집
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    • s.31
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    • pp.135-147
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    • 2001
  • The wall-thickness of insulated pipelines can be easily evaluated by measuring the gamma-ray transmission intensity because this intensity is inversely proportional to the thickness of insulated pipeline. The main purpose of this study is to develop the nondestructive and filmless on-line inspection system of corrosion by measuring the wall thickness of insulated pipeline. The inspection system is constructed with radioisotope, 64 channel photo diode array detector, crawler system and data taking and operating software. The traditional off-line radiographic method carried out by exposing film cassettes can be replaced by this cost-effective on-line digital imaging method and the application will be greatly expected especially in the chemical and petrochemical industries.

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Off-resonance Correction by Autofocus algorithm for Spiral Scan Imaging at 3Tesla MRI (자동초점 조절 방식을 통한 나선주사 영상의 off-resonance 보정 알고리즘)

  • Kang, Seung-Won;Kim, Pan-Ki;Cho, Sang-Heum;Ahn, Chang-Beom
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1920-1921
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    • 2007
  • 본 논문에서는 나선주사 영상에서 발생하는 off-resonance 현상에 의한 영상의 번짐을 보정하는 새로운 알고리즘을 제안하였다. 공간상에서의 inhomogeneity와 chemical-shift 현상으로 생기는 off-resonance 효과는 공간의 자장의 세기에 비례한다. 현재 사용되고 있는 보정 방법에서의 절차를 간소화 하고 보다 효과적인 보정 알고리즘을 적용함으로써 보다 나은 Spiral scan 영상을 얻고자 하였다.

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