• Title/Summary/Keyword: metallic oxide

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Study for the Standardization of Haematite and Comparison Property before and after Haematite Processing (대자석의 품질기준(品質基準) 및 포제전후의 성질비교)

  • Lee Jang-Cheon
    • Herbal Formula Science
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    • v.12 no.1
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    • pp.177-193
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    • 2004
  • Objectives: This study has been done to compare the Haematite's composition before and after using processing method and to clarify its quality and naming through the historical herbal books. Methods: I studied the Haematite and processed Haematite using physical and chemical methods which contain microscopic analysis, X-ray diffraction analysis, thermal analysis, XRF, ICP, etc, to compare the compositions and its characters. Results: Haematite is a metallic oxide(Hematite, $Fe_2O_3$). Haematite contains a main ingredients of crude Haematite Fe 40.336% - 62.174%, processed Haematite $50.499%{\sim}62.791%$(a theory value is 69.944% the korean pharmacopoeia wants >45%) and small ingredients, also. Conclusion: A radio-element contents of U, Th contain less than average contents of the lithosphere's U 1.8ppm, Th 7.2ppm.

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Synthesis and Conductivity Properties of $LaNiO_3$ Ceramic Conductors ($LaNiO_3$전도성 세라믹의 합성과 도전특성)

  • Cho, Jung-Ho;Cho, Joo-Hun;Kim, Kang-Eun;Chung, Su-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.406-409
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    • 2001
  • The conductivity properties and synthesis of $LaNiO_{3}$ ceramics from $La_{1+\delta}NiO_{3}(\delta=-0.06,0,0.06)$ were investigated. A single perovskite phase was realized at $800^{\circ}C$. $La_{2}NiO_{4}$ and other unexpected oxide were observed at $1000^{\circ}C$. The Microstructure was showed clearly that it is a low density porous material. $LaNiO_3$ ceramic showed a metallic conductivity. The conductivity of La rich samples had a higher value than the La poor samples.

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A Study on the Arsenic Removal Characteristics of TiO2 Powders in Ground Water (상용 TiO2의 지하수 비소제거 특성에 관한 연구)

  • Lee, Dong Ho;Kim, Sung Su
    • Journal of Korean Society on Water Environment
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    • v.31 no.6
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    • pp.632-636
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    • 2015
  • This study aims to evaluate arsenic adsorption efficiencies over various metal oxides (CeO2, TiO2, Fe3O4, ZrO2, AlOOH, SiO2, α-Al2O3, and γ-Al2O3) and investigate the correlation between physico-chemical characteristics of metal oxides and their efficiencies. From XPS, XRD BET analysis and isotherm adsorption test, TiO2 powder showed that the best adsorption efficiency, and it's mechanism was highly depended on the chemical adsorption.

Scattering analysis of laser beam drilling in porous ceramic materials (극초단 레이저를 이용한 기공성 세라믹 드릴링시 발생하는 레이저빔 산란해석)

  • Choi, Hae Woon
    • Laser Solutions
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    • v.15 no.4
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    • pp.6-11
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    • 2012
  • Laser beam can be either absorbed or scattered in porous ceramic material and its optical characteristics need to be understood. Electro-magnetic multiphysics software was used to simulate and understand the actual scattering phenomena in porous materials. 785nm femtosecond laser was irradiated on the surface of ceramic material and strong scattering occurred in drilling process. The computer results showed the scattering and absorption phenomena of Aluminum oxide were a mixture of dielectric and metallic material. The computer simulation showed the laser beam was almost extinct at the aspect rate of 5 approximately.

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ELECTROCHEMICAL PROCESSING OF USED NUCLEAR FUEL

  • Goff, K.M.;Wass, J.C.;Marsden, K.C.;Teske, G.M.
    • Nuclear Engineering and Technology
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    • v.43 no.4
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    • pp.335-342
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    • 2011
  • As part of the Department of Energy's Fuel Cycle Research and Development Program an electrochemical technology employing molten salts is being developed for recycle of metallic fast reactor fuel and treatment of light water reactor oxide fuel to produce a feed for fast reactors. This technology has been deployed for treatment of used fuel from the Experimental Breeder Reactor II (EBR-II) in the Fuel Conditioning Facility, located at the Materials and Fuel Complex of Idaho National Laboratory. This process is based on dry (non-aqueous) technologies that have been developed and demonstrated since the 1960s. These technologies offer potential advantages compared to traditional aqueous separations including: compactness, resistance to radiation effects, criticality control benefits, compatibility with advanced fuel types, and ability to produce low purity products. This paper will summarize the status of electrochemical development and demonstration activities with used nuclear fuel, including preparation of associated high-level waste forms.

The Formation Technique of Thin Film Heaters for Heat Transfer Components (열교환 부품용 발열체 형성기술)

  • 조남인;김민철
    • Journal of the Semiconductor & Display Technology
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    • v.2 no.4
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    • pp.31-35
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    • 2003
  • We present a formation technique of thin film heater for heat transfer components. Thin film structures of Cr-Si have been prepared on top of alumina substrates by magnetron sputtering. More samples of Mo thin films were prepared on silicon oxide and silicon nitride substrates by electron beam evaporation technology. The electrical properties of the thin film structures were measured up to the temperature of $500^{\circ}C$. The thickness of the thin films was ranged to about 1 um, and a post annealing up to $900^{\circ}C$ was carried out to achieve more reliable film structures. In measurements of temperature coefficient of resistance (TCR), chrome-rich films show the metallic properties; whereas silicon-rich films do the semiconductor properties. Optimal composition between Cr and Si was obtained as 1 : 2, and there is 20% change or less of surface resistance from room temperature to $500^{\circ}C$. Scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) were used for the material analysis of the thin films.

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Effect of Surface Treatment on the Formation of NiO Nanomaterials by Thermal Oxidation

  • Hien, Vu Xuan;Heo, Young-Woo
    • Applied Science and Convergence Technology
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    • v.25 no.6
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    • pp.149-153
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    • 2016
  • Thermal oxidation has significant potential for use in synthesizing metal-oxide nanostructures from metallic materials. However, this method has limited applicability to the synthesis of multi-morphology NiO from Ni foil. Techniques consisting of mechanical and chemical approaches were used to pre-treat the Ni foil (prior to oxidation) to promote the formation of nanowires and nanoplates on the NiO layer. These morphologies were realized on the Ni foils scratched by sand paper and a knife, respectively, and subsequently heat-treated at $500^{\circ}C$ for 24 h. Small nanowires (diameter: <10 nm) formed on the Ni foil treated by absolute $HNO_3$ and then oxidized at $500^{\circ}C$ for 24 h. The formation of various morphologies (on the pre-treated Ni foil), which differ from that formed in the case of pristine Ni foil after oxidation, may be attributed to the surface melting phenomenon that occurs during the nucleation process.

A Study of MgO Thin Film′s Properties Fabricated by ICP Magnetron Sputtering Method (유도결합 플라즈마 마그네트론 스퍼터링에 의한 MgO 박막의 특성 연구)

  • 김선호;주정훈
    • Journal of the Korean institute of surface engineering
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    • v.37 no.3
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    • pp.169-174
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    • 2004
  • MgO thin films were reactively deposited using an internal inductively coupled plasma assisted sputtering method varying reactive gas ratio to get stoichiometric film composition, and bipolar dc substrate bias to suppress micro arcs. The minimum frequency required for arc suppression was about 10KHz depending on ICP power. Their crystallinity was analyzed using X-ray diffraction and surface morphology using AFM. The surface was very smooth with rms roughness less than 0.42nm. The preferred orientation of the films were changing from (200) to bulk-like characteristics as Ar: $O_2$ratio was controlled to 10 : 2. Optical emission spectroscopy revealed that there were two distinct discharge modes: a blue one and a green one, where enhanced emission from Ar and Mg were observed. This cannot simply be understood by metallic or oxide mode of reactive sputtering due to ICP coupled to magnetron discharge.

Electrical properties of Organic TFT patterned by shadow-mask with all layer

  • Lee, Joo-Won;Kim, Jai-Kyeong;Jang, Jin;Ju, Byeong-Kwon
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.543-544
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    • 2006
  • Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide ($ZrO_2$) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility $.66\;cm^2$/V s and $I_{on}/I_{off}$>$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display.

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A Fundamental Study on the Properties of Color concrete Using Stained Agent (표면 착색용 산화제를 이용한 컬러 콘크리트의 기초 연구)

  • Park, Hyo-Jin;Lee, Won-Young;Lee, Kyung-Hyun;Choi, Duck-Jin;Kang, Cheol;Kim, Jin Man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.77-80
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    • 2009
  • Because buildings which apply color that is various to concrete recently are introduced, value as design element of building is rising gradually in townscape. Even if expense is increased according as importance of concrete that have variety of design because do such social background and connection is emphasized, development of color concrete is pressing. Therefore, in this research, examined concrete physical & chemical characteristics by use of acid agent as part of research to embody diverse surface color of cement material. Here, embodiment of various color by unique color that stained hydrate has as that Color Concrete forms stained oxide that react with hydrate within concrete spreading stained agent that contain acid and metallic-ion in matrix that have cement ingredient on the surface is available.

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