• Title/Summary/Keyword: Spectroscopy

Search Result 10,081, Processing Time 0.158 seconds

A Study on the Chemical Constituents from Marine Sponge Luffariella sp. (해면 Luffariella sp.의 화학적 성분 연구)

  • Park, Sun Ku;Kim, Sung Soo;Park, Jun Dae;Hong, Jung Sun;Kim, In Kyu
    • Journal of the Korean Chemical Society
    • /
    • v.39 no.7
    • /
    • pp.559-563
    • /
    • 1995
  • The three metabolites, Germacrene alcohol(1), Aaptamine(2) and Hexacyclic terpene(3) were isolated from Marine Sponge Luffariella sp., collected in October 1992, Manado Bay, Sulawesi in Indonesia showed in vitro activity against KB cancer cell line, and structure assignment for 1 was corrected by comparison of their spectral data with the literature $values^1$. Their structure were elucidated by $^1H$, $^13C$ NMR, $^1H$ $^13C$(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy$(HMQC)^2$, $^1H$ $^13C$(2 and 3 bond) Heteronuclear Multiple Bond Correlation Spectroscopy$(HMBC)^3$, Electron Impact Mass Spectroscopy(EI ms), Ultra-violet Spectroscopy(UV) and Infrared Spectroscopy(IR).

  • PDF

Study on Methods of Enhancement and Measurement of Corrosion Resistance for Subsea Equipment made of Aluminum (알루미늄으로 제작된 심해 장비의 부식 저항 능력 향상 방법 및 측정 방법 조사)

  • Seo, Youngkyun;Jung, Jung-Yeul
    • Plant Journal
    • /
    • v.16 no.3
    • /
    • pp.47-52
    • /
    • 2020
  • This study investigated the methodologies to enhance the corrosion resistance and the ways to measure for subsea equipment made of aluminum. The methodologies for the anticorrosion were cathodic protection, conversion coating, anodizing and organic coating. The simply analyzed ways to measure the corrosion resistance were Scanning Electron Microscope (SEM), Electrochemical Impedance Spectroscopy (EIS), Glow discharge optical emission spectrum spectroscopy (GD-OES), Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Scanning Vibrating Electrode Technique (SVET), contact angle and interfacial tension. The most widely used tools for increasing the corrosion resistance were the anodizing and the organic coating. Many ways were evenly used to measure corrosion. The methods more frequently utilized were SEM for the surface investigation and the contact angle to evaluate the corrosion resistance.

The Study of Two-dimensional Chemical Distribution about Soil using Laser Spectroscopy (레이저 분광법을 활용한 토양 2차원 화학적 분포도 검출 연구)

  • Yang, Jun-Ho;Yoh, Jai-Ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.45 no.6
    • /
    • pp.523-530
    • /
    • 2017
  • Laser-Induced Breakdown Spectroscopy (LIBS) which a plasma is irradiated at a specific wavelength depending on the material when a high-energy laser is irradiated, and a Raman spectroscopy which measures rotation and vibration in molecules as light-scattering phenomenon occurs, are attracting attention as a space exploration technology because of the advantages of high accuracy and real-time analysis, and the ability to perform long-range detection. In this study, the tendency of the laser spectrum according to the change of the soil component was analyzed by laser spectroscopy and the two - dimensional chemical distribution was conducted based on the trend of laser spectrum. We have also established the environment of Mars (4-7 torr) and lunar atmosphere (<1 torr) in experimental setup, to prove that it is possible to measure by difference of soil chemical composition using LIBS and Raman spectroscopy even in artificial space environment.

The Development of Quantification Technique for Brain In vivo Proton NMR Spectroscopy (뇌의 양성자 핵자기공명 분광학을 위한 정량화 방법 개발)

  • 강해진
    • Progress in Medical Physics
    • /
    • v.12 no.1
    • /
    • pp.31-39
    • /
    • 2001
  • NMR spectroscopy enables us to measure the molar concentration of the metabolites in the organisms, and this technique is the only method to measure the concentration non-invasively. The proton NMR spectroscopy has been used to study the biochemical changes in human as well as in animal brain. MRI uses the proton densities and its relaxation times for reconstructing images, but MRS gives the biochemical changes inside the body. NMR spectroscopy could provide the information which MRI and CT could not, and this makes NMR spectroscopy more useful in diagnosing diseases. This study was tried to develop the quantitation of the molar concentration of the metabolites in the brain using the proton MR spectroscopy. The spectra of each metabolites was obtained, and the proton MR spectra was obtained from the insula gray matter areas of the 16 volunteers. And this spectra was analyzed to estimated the molar concentrations of the metabolites in the region. The results showed the very similar to those of the others.

  • PDF

Dark Resonance and Its Potential Applications: High-Resolution Spectroscopy

  • Ham, Byoung-Seung
    • Journal of the Optical Society of Korea
    • /
    • v.5 no.3
    • /
    • pp.110-116
    • /
    • 2001
  • Recently observed dark resonance phenomena is solids are reviewed and discussed for potential applications to high-resolution coherence spectroscopy. in an inhomogeneously broadened system, a new type of high-resolution spectroscopy based on electromagnetically induced transparency is demonstrated.