• Title/Summary/Keyword: Mo/Rh

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Sonochemical Synthesis of $PbMoO_4$ Nanoparticles and Evaluation of its Photocatalytic Activity

  • Uresti, Diana B. Hernandez;De la Cruz, Azael Martinez;Martinez, Leticia M. Torres;Lee, Soo-Wohn
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.49.2-49.2
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    • 2011
  • $PbMoO_4$ nanoparticles were successfully obtained in the presence of ethylene glycol (EG) with the assistance of a prolonged sonication process. The nanoparticles were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and adsorption-desorption $N_2$ isotherms (BET). The catalyst prepared sonochemically showed higher photocatalytic activity than $PbMoO_4$ prepared by solid-state reaction in the degradation reactions of rhodamine B (rhB), indigo carmine (IC), orange G (OG), and methyl orange (MO) under UV-Vis light radiation. In order to elucidate aspects of the degradation mechanism of the organic dyes, some experimental variables were modified such as pH, $O_2$ level in solution, and radiation source. In general, the photocatalytic activity for the degradation of organic dyes followed the sequence IC>OG>rhB>MO.

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Effects of Triterpence Acids and Ginsenosides in Differentiation of HL-60 Promyelocytic Leckemia Cells (HL-60 세포에 대한 Triterpent Acids와 Ginsenosides의 분화효과)

  • Kang, Chang-Mo;Lee, Ho-Young;Kim, Shin-Il;Kim, Kyu-Won
    • Journal of Life Science
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    • v.8 no.2
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    • pp.162-166
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    • 1998
  • The acute myelogeous leukemia cell line, HL-60 is good model to examine leukemia differentiation with nitro blue terazolium reduction assay. We investigated that effect of triterpene acids and ginseng saponin on differentiation of HL-60 cells. Differentiation of HL-60 cells was induced in proportion to ,olar concentration by dibutylyl cAMP, ginseng saponin, lithocholic acid, ginsenoside RH2, and ginsenoside RH3.

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Preparation of Bi/Bi2MoO6 Plasmonic Photocatalyst with High Photocatalytic Activity Under Visible Light Irradiation

  • Zou, Chentao;Yang, Zhiyuan;Liang, Mengjun;He, Yunpeng;Yang, Yun;Yang, Shuijin
    • Nano
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    • v.13 no.11
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    • pp.1850127.1-1850127.13
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    • 2018
  • Bi metal deposited on $Bi_2MoO_6$ composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using $NaBH_4$ as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of $Bi/Bi_2MoO_6$ composite to RhB is 10.8 times that of $Bi_2MoO_6$, and the degradation rate constant of BPA is 6.9 times of that of $Bi_2MoO_6$. Nitrogen absorption-desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of $Bi/Bi_2MoO_6$ composites. The higher charge transfer efficiency of $Bi/Bi_2MoO_6$ is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.

Few-Layered MoS2 Nanoparticles Loaded TiO2 Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity

  • Chen, Chujun;Xin, Xia;Zhang, Jinniu;Li, Gang;Zhang, Yafeng;Lu, Hongbing;Gao, Jianzhi;Yang, Zhibo;Wang, Chunlan;He, Ze
    • Nano
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    • v.13 no.11
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    • pp.1850129.1-1850129.10
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    • 2018
  • To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed $TiO_2$ [$TiO_2(001)$] nanosheets, few-layered $MoS_2$ nanoparticles were loaded on the surfaces of $TiO_2(001)$ nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the $MoS_2-TiO_2(001)$ nanocomposites exhibited much enhanced photocatalytic activities compared with the pure $TiO_2(001)$ nanosheets. At an optimal Mo/Ti molar ratio of 25%, the $MoS_2-TiO_2(001)$ nanocomposites displayed the highest photocatalytic activity, which took only 30 min to degrade 50 mL of RhB (50 mg/L). The active species in the degradation reaction were determined to be $h^+$ and $^{\bullet}OH$ according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% $MoS_2-TiO_2(001)$ nanocomposites.

Neutron Cross Section Evaluation on Mo-95, Tc-99, Ru-101 and Rh-1()3 in the Fast Energy Region

  • Lee, Y. D.;J. H. Chang
    • Nuclear Engineering and Technology
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    • v.34 no.6
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    • pp.533-544
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    • 2002
  • The neutron induced nuclear data for Mo-95, Tc-99, Ru-101 and Rh-103 was calculated and evaluated in the fast energy region. The energy dependent optical model potential parameters were extracted based on the recent experimental data and applied up to 20 MeV. The s-wave strength function was calculated from the parameters. Spherical optical model, statistical model in equilibrium energy, multistep direct and multistep compound model in pre-equilibrium energy and direct capture model were used in the calculation. The theoretically calculated cross sections were compared with the experimental data and the evaluated files The model- calculated total and capture cross sections were in good agreement with the reference experimental data. The direct capture contribution improved the capture cross sections in pre- equilibrium region. The evaluated cross section results were compiled to ENDF-6 format and will improve the ENDF/B-Vl.

A Study on the Actual Conditions and Characteristics of Mammographic Units in Some Area (일부지역 유방촬영장치의 현황 및 특성에 관한 연구)

  • Park, Jin-Young;Baek, Seong-Min
    • Journal of the Korean Society of Radiology
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    • v.6 no.2
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    • pp.121-127
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    • 2012
  • Of this study, it was found that there were 250 mammographic units in total installed and used in the areas for this study, and 36 units were used in general hospitals, 53 units in hospitals and 116 units in clinics. That is, the units in clinics accounted for 50% out of the whole units. As for the image acquisition method, it was found there were 131 units using F/S, 67 units using CR and 7 units using DR respectively. At present, F/S system was mainly used in the areas. As for the materials of target/filter, it was found that Mo/Mo was mostly used (66%), followed by Mo/Rh (25%). As for the size of focus, both 0.1 mm for small focus and 0.3 mm for large focus were mainly used for the units.

Determination of Fission Products in Simulated Nuclear Spent Fuels by Cation.Anion Exchange Chromatography and Inductively Coupled Plasma Atomic Emission Spectrometry (양.음이온교환 크로마토그래피와 유도결합플라스마 원자방출분광법을 이용한 모의 사용후핵연료 중 핵분열생성물 분석)

  • Choi, Kwang Soon;Sohn, Se Chul;Pyo, Hyung Yeol;Suh, Moo Yul;Kim, Do Yang;Park, Yang Soon;Jee, Kwang Yong
    • Analytical Science and Technology
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    • v.13 no.4
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    • pp.446-452
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    • 2000
  • The simulated nuclear spent fuel (SIMFUEL) containing the platinum group elements which will not be dissolved in a nitric acid was completely dissolved with a acid digestion bomb. The metallic elements separated in the SIMFUEL were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). Because the peaks of metallic elements were spectrally interfered by uranium spectrum, uranium and metallic elements were separated by cation exchange resin for Mo, Pd, Rh and Ru and by anion exchange resin for Ba, Ce, La, Nd, Rh, Sr, Y and Zr, respectively. The recovery of Mo, Pd, Rh and Ru after separation by cation exchange chromatography found to be 99-103% and anion exchange separation showed 96.5-107% of recovery except Y with the simulated solution whose concentration was similar to the spent nuclear fuel. The relative standard deviation of this method showed 1.3-6.7% in the SIMFUEL whose concentrations of metallic elements were between several $10^2-10^3$ppm.

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Analysis of High Radioactive Materials in Irradiated DUPIC SIMFUEL Using EPMA (EPMA를 이용한 DUPIC 사용후 핵연료 핵분열 생성물의 특성 분석)

  • 정양홍;유병옥;주용선;이종원;정인하;김명한
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.2
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    • pp.125-133
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    • 2004
  • Fission products of DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactors) fuel, irradiated in HANARO research reactor with 61 ㎾/m of maximum linear power and 1,770 ㎿d/tU of average burn-up, was characterized by EPMA(Electron Probe Micro Analyzer). In order to find accurate characterization, the analysis results by EPMA of fresh simulated DUPIC fuel containing fission products as chemicals were compared with that of wet chemical analysis. The metallic precipitates observed at the center of the fresh simulated DUPIC fuel were about 1 $\mu\textrm{m}$ in size and their major components by EPMA were Mo-53.89 at.%, Ru-37.40 at.%, and Pd+Rh-8.71 at.%. Established procedure through the fresh simulated DUPIC fuel was applied to the irradiated DUPIC fuel. Observed size of metallic precipitates were 2∼2.5 $\mu\textrm{m}$ and their compositions were Mo-47.34 at.%, Ru-46 at.%, and Pd+Rh-6.65 at.%. What are uncommon things for this experiment, special treatment for improving the conductivity was attempted to the specimen and the conditions of exact irradiation of electron beam to small metallic precipitate were suggested.

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