• Title/Summary/Keyword: Ultraviolet detection

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Detection of the fluorescent emission of hydrogen in the Taurus cloud

  • Dae-Hui Lee;In-Su Yuk;Jang-Hyeon Park;Ho Jin;Gwang-Il Seon;Uk-Won Nam;Won-Yong Han;Gyeong-Uk Min;Gwang-Seon Yu
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.99-99
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    • 2004
  • We detected and analyzed molecular hydrogen fluorescence in the Taurus Cloud using the Far-ultraviolet Imaging Spectrograph (FIMS) on the STSAT-1 which was launched at SeP. 27 2003. FIMS is optimized for observing diffuse emission lines in the interstellar medium in the wavelength bands of 900-l150 and 1300-1700 angstrom. The Taurus region is a local molecular cloud which is good for studying molecular hydrogen fluorescence emissions. (omitted)

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PERIODIC VARIABILITY OF RY Tau

  • ISMAILOV, NARIMAN Z.;ADIGEZALZADE, H.N.;BAHADDINOVA, G.R.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.229-230
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    • 2015
  • The results of spectral studies of the CTTS type young star RY Tau with spectrograms of the ultraviolet and the visual ranges are presented. We show the first detection of periodic variability of the emission line intensities in UV and visual ranges with a period of 23 days.

Separation and Detection of Nonchromophore Aliphatic Compounds by Reversed-Phase Liquid Chromatography using Ultraviolet-Absorbing Reagent (자외선 흡수물질을 이용한 역상 액체 크로마토그라피에 의한 비흡수 지방족 화합물들의 검출과 분리)

  • Lee Seung-Seok;Kang Sam-Woo;Oh Hae-Beom
    • Journal of the Korean Chemical Society
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    • v.35 no.4
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    • pp.397-404
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    • 1991
  • Nonchromophore compounds such as aliphatic acids, alcohols and tetraalkylammonium salts could be detected by indirect photometric detection on the revered-phase liquid chromatography. Benzyltriethylammonium bromide(BTEAB) was used as a detection reagent. Also, the retention mechanism and response of samples were investigated to the several factors such as pH, temperature, and concentration of MeOH as well as concentration of detection reagents in mobile phase. And some mixture of samples were able to be separated under optimum condition.

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Mass Spectrometry-Based Analytical Methods of Amatoxins in Biological Fluids to Monitor Amatoxin-Induced Mushroom Poisoning

  • Choi, Jin-Sung;Lee, Hye Suk
    • Mass Spectrometry Letters
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    • v.13 no.4
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    • pp.95-105
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    • 2022
  • Amatoxin-induced mushroom poisoning starts with nonspecific symptoms of toxicity but hepatic damage may follow, resulting in the rapid development of liver insufficiency and, ultimately, coma and death. Accurate detection of amatoxins, such as α-, β-, and γ-amanitin, within the first few hours after presentation is necessary to improve the therapeutic outcomes of patients. Therefore, analytical methods for the identification and quantification of α-, β-, and γ-amanitin in biological samples are necessary for clinical and forensic toxicology. This study presents a literature review of the analytical techniques available for amatoxin detection in biological matrices, and established an inventory of liquid chromatography (LC) techniques with mass spectrometry (MS), ultraviolet (UV) detection, and electrochemical detection (ECD). LC-MS methods using quadrupole tandem mass spectrometry, time-of-flight mass spectrometry, and orbitrap MS are powerful analytical techniques for the identification and determination of amatoxins in plasma, urine, serum, and tissue samples, with high sensitivity, specificity, and reproducibility compared to LC with UV and ECD, enzyme-linked immunoassay, and capillary electrophoresis methods.

Algorithm for Detection of Solar Filaments in EUV

  • Joshi, Anand D.;Cho, Kyung-Suk
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.66.2-66.2
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    • 2015
  • In today's age when telecommunications using satellite has become part of our daily lives, one has to be employ preventive measures to avert any possible danger, of which solar activity is the major cause. Coronal mass ejections (CMEs) heading towards the Earth can lead to disturbances in the Earth's magnetosphere, if their magnetic field is oriented southward. Monitoring of solar filaments in this case becomes very very crucial, as their eruption is associated with most of the CMEs. Monitoring of solar filaments in this case becomes very very crucial, as their eruption is associated with most of the CMEs. Also, filaments show activation up to a few hours prior to launch of a CME and thus can provide advance warning. In this study, we present an algorithm for the detection of solar filaments seen in the extreme ultraviolet (EUV) from Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Various morphological operations are employed to identify and extract the filaments. These filaments are then tracked in order to determine their size and location continuously.

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Detection and Measurement of Non-ionizing Radiations (비전리방사선의 검출 및 측정)

  • Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.20 no.3
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    • pp.155-162
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    • 1995
  • The state-of-the art of detection and measurements of non-ionizing radiations are reviewed in relation to protection requirements, especially for electromagnetic and ultraviolet radiations. Dosimetric quantities, instruments and considerations needed for measurement are briefly explained. For electromagnetic radiation, the power density levels from various practical sources are summarized for reference uses. Large errors remain in the measurements of non-ionizinf radiations in general. Technical needs of development in measurement and dosimetry of non-ionizing radiations, therefore, are promissing when the increasing public concerns about the adverse health effects of non-ionizing radiations and proliferation of their uses are taken into account.

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Simultaneous Determination of Abamectin and Milbemectin Residues in Fruits

  • Lee, Young-Deuk;Kwon, Chan-Hyeok
    • Journal of Applied Biological Chemistry
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    • v.43 no.2
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    • pp.94-100
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    • 2000
  • An analytical method was developed to determine abamectin and milbemectin residues in apple, pear, and citrus using HPLC with ultraviolet absorption detection. Abamectin and milbemectin were extracted with methanol from apple, pear, and citrus samples. The extract was diluted with saline water and dichloromethane partition was followed to recover the compounds from the aqueous phase. Florisil column chromatography and aminopropyl solid-phase extraction were employed as cleanup methods to remove most of co-extractives from the sample extract. Reverse-phase HPLC using an octadecylsilyl column was successfully applied to separate and quantitate abamectin and milbemectin residues in sample extracts at the wavelength of 245 nm. Recoveries of abamectin and milbemectin from fortified samples ranged 80.4~90.3% and 90.9~96.8%, respectively. Relative standard deviations of the analytical method were less than 10% for both acaricides. Detection limit of the analytical method was 0.003 mg/kg sample for all the analytes. The proposed method was reproducible and sensitive enough to evaluate terminal residues of abamectin and milbemectin in apple, pear, and citrus.

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Detection of a Large Amount of Diffuse Extraplanar Dust in NGC 891

  • Seon, Kwang-Il;Witt, Adolf
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.71.1-71.1
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    • 2011
  • Significant discrepancies have been found between the dust masses of edge-on spiral galaxies derived from various tracers (optical/near-infrared, far-infrared/sub-millimeter observations, and the variation of dust attenuation with viewing angle). Here we report the first detection of a vertically extended far-ultraviolet (FUV) and near-UV (NUV) emission in an edge-on spiral galaxy NGC 891. The vertically extended emission is interpreted as the dust-scattered light due to a extraplanar dust layer in NGC 891 that contains about the same mass as the standard thin dust disk. This new dust component completely encloses the stellar disk and bulge, and solves the puzzle of dust mass.

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Multiresidue Analysis of Eight Acaricides in Fruits

  • Lee, Young-Deuk;Kwon, Chan-Hyeok
    • Journal of Applied Biological Chemistry
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    • v.42 no.4
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    • pp.191-196
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    • 1999
  • A multiresidue analytical method was developed for eight acaricides including benzoximate, clofentezine, fenazaquin, fenothiocarb, fenpyroximate, hexythiazox, pyridaben, and tebufenpyrad in four major fruits using high-performance liquid chromatography (HPLC). All the confounds were extracted with acetone from apple, pear, grape, and citrus samples. The extract was diluted with saline water, and n-heaxane partition was followed to recover the acaricides. Florisil column chromatography was employed to further purify the sample extract. HPLC with ultraviolet absorption detection, using an octadecylsilyl column under the isocratic mobile phase of acetonitrile/water mixture, was successfully applied to separate and quantitate all the compounds in the purified extract. Recoveries of the eight acaricides from for fortified samples ranged 86.4~97.0%. Relative standard deviations of the analytical method were all less than 10%. Detection limits of the method were in the range of 0.02~0.05 mg/kg. The proposed method was reproducible and sensitive enough to evaluate the terminal residue of the eight acaricides in the fruit harvest.

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Fabrication of Polyimide Film Electrode by Laser Ablation and Application for Electrochemical Glucose Biosensor (Laser ablation을 이용한 폴리이미드 필름 전극제조 및 전기화학적 글루코오즈 바이오센서 응용)

  • Park, Deog-Su
    • Journal of Sensor Science and Technology
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    • v.22 no.5
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    • pp.357-363
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    • 2013
  • An ultraviolet pulsed laser ablation of polyimide film coated with platinum has been used to enhance the sensitivity for the application as an electrochemical biosensor. Densely packed cones are formed on polyimide surface after UV irradiation which results in increase of surface area. In order to apply the sensitivity improvement of laser ablated polyimide film electrodes, the glucose oxidase modified biosensor was fabricated by using an encapsulation in the gel matrix through sol-gel transition of tetraethoxysliane on the surface of laser ablated polyimide film. The optimum conditions for glucose determination have been characterized with respect to the applied potential and pH. The linear range and detection limit of glucose detection were from 2.0 mM to 18.0 mM and 0.18 mM, respectively. The sensitivity of glucose biosensors fabricated with laser ablated polyimide film is about three times higher than that of plain polyimide film due to increase in surface area by laser ablation.