• Title/Summary/Keyword: Advanced Oxidation

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Assessment of the severe accident code MIDAC based on FROMA, QUENCH-06&16 experiments

  • Wu, Shihao;Zhang, Yapei;Wang, Dong;Tian, Wenxi;Qiu, Suizheng;Su, G.H.
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.579-588
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    • 2022
  • In order to meet the needs of domestic reactor severe accident analysis program, a MIDAC (Module Invessel Degraded severe accident Analysis Code) is developed and maintained by Xi'an Jiaotong University. As the accuracy of the calculation results of the analysis program is of great significance for the formulation of severe accident mitigation measures, the article select three experiments to evaluate the updated severe accident models of MIDAC. Among them, QUENCH-06 is the international standard No.45, QUENCH-16 is a test for the analysis of air oxidation, and FROMA is an out-of-pile fuel rod melting experiment recently carried out by Xi'an Jiaotong University. The heating and melting model with lumped parameter method and the steam oxidation model with Cathcart-Pawel and Volchek-Zvonarev correlations combination in MIDAC could better meet the needs of severe accident analysis. Although the influence of nitrogen still need to be further improved, the air oxidation model with NUREG still has the ability to provide guiding significance for engineering practice.

High-temperature oxidation of Ti3(Al,Si)C2 nano-laminated compounds in air

  • Lee, Hwa-Shin;Lee, Dong-Bok
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.11a
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    • pp.147-148
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    • 2007
  • The compound, Ti3(Al,Si)C2, was synthesized by hot pressing a powder mixture of TiCX, Al and Si. Its oxidation at 900 and 1000 oC in air for up to 50 h resulted in the formation of rutile-TiO2, -Al2O3 and amorphous SiO2. During oxidation, Ti diffused outwards to form the outer TiO2 layer, and oxygen was transported inwards to form the inner mixed layer.

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Progresses in membrane and advanced oxidation processes for water treatment

  • Khulbe, K.C.;Feng, C.Y.;Matsuura, T.;Ismail, A.F.
    • Membrane and Water Treatment
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    • v.3 no.3
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    • pp.181-200
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    • 2012
  • At present water crisis is not an issue of scarcity, but of access. There is a growing recognition of the need for increased access to clean water (drinkable, agricultural, industrial use). An encouraging number of innovative technologies, systems, components, processes are emerging for water-treatment, including new filtration and disinfectant technologies, and removal of organics from water. In the past decade many methods have been developed. The most important membrane-based water technologies include reverse osmosis (RO), ultrafiltration (UF), microfiltration (MF), and nanofiltration. Beside membrane based water-treatment processes, other techniques such as advanced oxidation process (AOP) have also been developed. Some unconventional water treatment technology such as magnetic treatment is also being developed.

Rapid Fabrication of Cu/Cu2O/CuO Photoelectrodes by Rapid Thermal Annealing Technique for Efficient Water Splitting Application

  • Lee, Minjeong;Bae, Hyojung;Rho, Hokyun;Burungale, Vishal;Mane, Pratik;Seong, Chaewon;Ha, Jun-Seok
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.4
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    • pp.39-45
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    • 2020
  • The Cu/Cu2O/CuO photoelectrode has been successfully fabricated by Rapid Thermal Annealing technique. The structural characterization of fabricated photoelectrode was performed using X-Ray diffraction, while elemental composition of the prepared material has been checked with X-Ray Photoelectron Spectroscopy. The synthesis parameters are optimized on the basis of photoelectrochemical performance. The best photoelectrochemical performance has been observed for the Cu/Cu2O/CuO photoelectrode fabricated at 550 ℃ oxidation temperature and oxidation time of 50 seconds with highest photocurrent density of -3 mA/㎠ at -0.13 V vs. RHE.

Tunnel i unction-Mangnetorsistance in Co-Al-O$_{x}$-NiFe with oxidation conditions of Al thickness

  • Jeon, Dong-Min;Park, Jin-Woo;Suh, Su-Jeong
    • Journal of the Korean institute of surface engineering
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    • v.34 no.5
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    • pp.494-498
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    • 2001
  • Ferromagnets(FM)-Al-$O_{x}$ -Ferromagnets (FM) tunneling junctions were evaluated by changing the fabricating conditions of an Al-X$/_{x}$ layer. The junction composed of a thicker Al-$O_{x}$ shows the low resistance and the stable MR ratio about 16% in a wide range of oxidation time. For the junctions with the thinner Al-$O_{x}$ , they showed a fast increase of the barrier width as an increase of an oxidation time and exhibited a strong bias dependence. As oxidation time increased, the coercivity ($H_{c}$ ) of bottom Co layer increased gradually due to the local oxidation of Co bottom layer at a interface. However, the small formation of Co oxide did not largely influence on the deterioration of MR ratio.

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Effect of Mo and Nb on High Temperature Oxidation of TiAl Alloys (Mo, Nb첨가가 TiAl합금의 산화에 미치는 영향)

  • Kim Jae-Woon;Lee Dong-Bok
    • Korean Journal of Materials Research
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    • v.14 no.9
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    • pp.614-618
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    • 2004
  • Alloys of $Ti46\%Al-2\%Mo-2\%Nb$ were oxidized between 800 and $1000^{\circ}C$ in air, and their oxidation characteristics were studied. The alloys displayed good oxidation resistance due mainly to the beneficial effects of Mo and Nb. The oxide scales formed consisted primarily of an outer $TiO_2$ layer, an intermediate $Al_{2}O_3-rich$ layer, and an inner mixed layer of ($TiO_{2}+Al_{2}O_3$). Molybdenum and niobium dissolved in the scale effectively improved oxidation resistance. They were mainly distributed in the inner mixed layer of ($TiO_{2}+Al_{2}O_3$).

High Temperature Oxidation of Thermomechanically Treated Ti-45.4%Al-4.8%Nb Alloys (열기계적 처리한 Ti-45.4%Al-4.8%Nb 합금의 고온산화)

  • Kim Jae-Woon;Lee Dong-Bok
    • Korean Journal of Materials Research
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    • v.14 no.7
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    • pp.457-461
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    • 2004
  • The thermomechanically treated $Ti-45.4\%Al-4.8\%Nb(at\%)$ alloy was oxidized between 800 and $1000^{\circ}C$ in air, and the oxidation characteristics were studied. The dissolution of Nb in the oxide scale was observed from the TEM study. The Pt marker test revealed that the oxidation process was controlled by the outward diffusion of Ti ions and the inward diffusion of oxygen ions. During oxidation, the evaporation of Nb-oxides was found to occur to a small amount. Niobium tended to pile-up at the lower part of the oxide scale, which consisted primarily of an outer $TiO_2$ layer, and an intermediate $Al_{2}O_{3}-rich$ layer, and an inner mixed layer of ($TiO_{2}+Al_{2}O_{3}$).

High-temperature Oxidation of Nano-multilayered AlTiSiN Thin Films deposited on WC-based carbides

  • Hwang, Yeon Sang;Lee, Dong Bok
    • Corrosion Science and Technology
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    • v.12 no.3
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    • pp.119-124
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    • 2013
  • Nano-multilayered, crystalline AlTiSiN thin films were deposited on WC-TiC-Co substrates by the cathodic arc plasma deposition. The deposited film consisted of wurtzite-type AlN, NaCl-type TiN, and tetragonal $Ti_2N$ phases. Their oxidation characteristics were studied at 800 and $900^{\circ}C$ for up to 20 h in air. The WC-TiC-Co oxidized fast with large weight gains. By contrast, the AlTiSiN film displayed superior oxidation resistance, due mainly to formation of the ${\alpha}-Al_2O_3$-rich surface oxide layer, below which an ($Al_2O_3$, $TiO_2$, $SiO_2$)-intermixed scale existed. Their oxidation progressed primarily by the outward diffusion of nitrogen, combined with the inward transport of oxygen that gradually reacted with Al, Ti, and Si in the film.