• Title/Summary/Keyword: SEM/EDX analysis

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Concentration Characteristics of Indoor and Outdoor Airborne Total Fiber Particles and Identification of Asbestos in Gyeongnam Provinces (경남지역의 실내외 공기 중 총섬유 입자의 농도특성 및 석면 입자의 확인)

  • Park, Hee-Eun;Park, Jeong-Ho;Kim, Hyoung-Kab
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.22 no.2
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    • pp.119-127
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    • 2012
  • Objectives: The aim of this study is to identify concentration characteristics of indoor and outdoor airborne total fiber particles and asbestos in Gyeongnam Provinces. Methods: This study investigated concentration characteristics of indoor fiber particles from 748 schools and 38 public facilities as well as outdoor particles from 11 sites through PCM (phase contrast microscope). SEM/EDX (scanning electron microscope/energy dispersive using X-ray analysis) was used to obtain physicochemical information of asbestos fiber particles. The study identified asbestos rate in the 15 samples from indoor and outdoor airborne total fiber particles. Results: 1. The average indoor airborne concentrations of total fiber particles were $0.0011{\pm}0007$ f/cc in schools and $0.0015{\pm}0007$ f/cc in public facilities by PCM. Over 90% of the fiber particles were identified as single fibers. 2. The average outdoor airborne concentrations of total fiber particles were $0.0007{\pm}0002$ f/cc, and they were lower than those of indoor airborne concentrations. 3. The results showed that the form of asbestiform was diverse as skein of thread like form and long needle, which was relatively narrower than that of glass fiber and rock wool. 4. The results of SEM/EDX analysis of 15 areas where total fiber particle was relatively high showed that the form was rather similar to that of asbestos, but chemical composition was proven to be non-asbestos. Conclusions: The concentration of indoor and outdoor airborne total fiber particles of Gyeongnam Provinces satisfied the IAQ (Indoor air quality) level of 0.01 f/cc and asbestos was not found in most of the samples by SEM/EDX.

Classification of Individual Ambient Particles by CCSEM (CCSEM을 이용한 대기 중 개별분진의 분류에 관한 연구)

  • 장여진;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.5
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    • pp.345-353
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    • 1997
  • The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.

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Mineralogical Properties of the Sedimental Clay in Ulsan (울산퇴적점토의 광물조성 특성)

  • 민덕기;황광모;강문기;박종규
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.567-574
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    • 2000
  • The purpose of this study is to examine mineralogical properties of the soft clay that is distributed widely in Samsan area, Ulsan. XRD analysis were examined to find the quantities of the clay minerals. And XRF, SEM and EDX analysis were also examined to investigate the chemical compositions and the structures of the clay. The properties of the samples from 2 sites in Samsan area were that the minerals of the clay were illite, kaolinite, chlorite, smectite and etc.. The plenty of illite has 38 to 53% of content in whole study area. And kaolinite had 18 to 30%, chlorite had 15 to 25%, and smectite had 4 to 12% of content, respectively. The results of SEM observation showed that appearances of Ulsan clay were sheet, plannar or needle form. Ulsan clay included the salt crystal of cubic and the foraminifera, which were related with the content of organ.

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Photocatalytic activity of Fe treated AC/TiO2 composites between visible light and UV light irradiation (가시광선과 UV광선에 의한 Fe 처리된 AC/TiO2 복합체의 광분해활성)

  • Meng, Ze-Da;Zhang, Kan;Oh, Won-Chun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.5
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    • pp.1760-1767
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    • 2010
  • FAT compounds photocatalysts were prepared with $TiOSO_4{\cdot}xH_2O$ (TOS) by a sol-gel method. The samples were characterized by scanning electron microscopy (SEM), BET specific surface area, X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDX). The SEM results showed that ferric compounds and titanium dioxide were fixed onto the AC surfaces. The XRD results showed that Fe-AC/$TiO_2$ composites mostly contained anatase phase. EDX showed the presence of C, O, and Ti with Fe peaks in all samples. The photocatalytic activities were evaluated by the photocatalytic oxidation of methylene blue (MB) solution, via compare photodegradation of MB solution under visible light and UV light separately. Fe-AC/$TiO_2$ composites had an excellent photocatalytic under strong visible light irradiation. A small amount of Fe ions in AC/$TiO_2$ particles could obviously enhance their photocatalytic activity.

Variation of Carbonization Pattern and Crystal Structure of Polyvinyl Chloride Wire Under the Thermal Stresses (열 스트레스에 의한 비닐절연전선의 탄화 패턴 및 결정 구조의 변화)

  • Choi, Chung-Seog;Kim, Hyang-Kon
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.3
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    • pp.332-337
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    • 2008
  • We analyzed carbonization pattern and crystal structure of polyvinyl chloride wire by thermal stress. Copper that is oxidized at normal temperature is a reddish brown. If under the thermal stress range of 500 to 700 [$^{\circ}C$], carbonization and exfoliation occurrence. Section structure of electric wire is same as arrangement of particle in metallograph analysis. But, as thermal stress increases, size of particle is enlarged. Electric wire displays elongation structure in SEM image analysis and elongation structure collapses when receive thermal stress at 300 [$^{\circ}C$]. In EDX analysis, we get the spectra of CuL, CuK, OK, and ClK. FT-IR analysis was shown new spectra with in range of $1,440{\sim}1,430\;[cm^{-1}]$, 1,340 [$cm^{-1}$], 1,240 [$cm^{-1}$].

Individual Particle Analysis for Developing a Source Profile of Yellow Sands (황사의 오염원분류포 개발을 위한 개별입자분석)

  • 강승우;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.565-572
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    • 2000
  • To quantitatively estimate mass contribution of long-range transported yellow sand, their sources should be separated independently from various local soil sources having similar elemental compositions. While it is difficult to estimate total mass loadings of pure yellow sand by traditional bulk analysis, it can be clearly solved by an particle-by-particle analysis. To perform this study, two yellow sand samples and three local soil samples were collected by a mini-volume sampler. These samples were three analyzed using a scanning electron microscope(SEM) equipped with an energy dispersive x-ray analyser (EDX) was used to obtain basic chemical information of individual yellow san particles. A total of 19 elements in a single particle were measured to develop a source profile with newly created homogeneous particle classes (HPCs) as chemical variables. The present study showed that the yellow sand samples as well as three local soil samples were characterized with reasonably well created HPCs. Finally the mass fraction of each HPC in each sample was calculated and then compared each other.

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A Study on the Ignition and Molten Mark Analysis of Ballast for Fluorescent Lamp (형광등용 안정기의 발화 및 용융흔 분석에 관한 연구)

  • 최충석;박창수;김혁수;김향곤;정재희
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 1998.11a
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    • pp.173-177
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    • 1998
  • In this paper, we reported an outbreak of fire hazard of ballast for fluorescent lamp. The surface structure and composition of ballast coil analyzed by using metallurgical microscope, scanning electron microscope(SEM) and energy dispersive x-ray spectroscopy(EDX). The surface of molten mark appeared columnar structure and void. EDX analysis indicated that the molten mark spectra were composed not only of the corresponding original spectra but also of several new lines.

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Characterizations of Airborne Fiber Particle Concentrations in Public Facilities and Schools (다중이용시설 및 학교 교사내 실내공기중 섬유상 입자의 농도 특성)

  • Park, Jeong-Ho;Suh, Jeong-Min
    • Journal of Environmental Science International
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    • v.19 no.4
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    • pp.509-516
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    • 2010
  • This study was investigated the characteristics of indoor air concentration of fiber particles in 30 public facilities and 245 schools by PCM (phase contrast microscopy). Also SEM/EDX (scanning electron microscope / energy dispersive using X-ray analysis) was used to obtain physicochemical information of asbestos fiber and to classify asbestos and non-asbestos of fiber particles. The airborne concentrations of fiber particles were $0.0009\pm0.0009$ counts/mL in public facilities and $0.0012\pm0.0006$ counts/mL in schools by PCM. All the samples were satisfied with the IAQ (indoor air quality) level of 0.01 counts/mL. In classification of 4 type shapes, over 80% of the fiber particles were identified as single fiber type. And this study analysed airborne fiber particles in 4 sites for identifying asbestos of by SEM/EDX. The asbestos fibers in most samples could not be found.

Potassium loading effects for activated carbon fiber pre-treated with phosphoric acid (인산을 전처리한 활성탄소섬유에 칼륨 처리효과)

  • Oh, Won-Chun;Bae, Jang-Soon
    • Analytical Science and Technology
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    • v.18 no.4
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    • pp.355-361
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    • 2005
  • The objective of this paper is to compare the surface features of two kinds of activated caron fiber (ACF) treated with potassium and the variation of their properties by phosphoric acid pre-treatment. X-ray diffraction (XRD) patterns indicate that activated carbon fiber containing potassium species show better performance for metal and metal salts by pre-treatment with phosphoric acid. In order to present the causes of the differences in surface properties and specific surface area after the samples were treated with phosphoric acid, pore structure and surface morphology were investigated by adsorption analysis and SEM. For the chemical composition microanalysis for potassium leading of the activated carbon fibers pre-treated with phosphoric acid, samples were analyzed by EDX. Finally, the type and quality of oxygen groups were determined from the method proposed by Boehm.