| 1. |
- Pham, M. K., et al.
(författare)
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Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)
- 2006
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Ingår i: Proceedings of the 15th International Conference on Radionuclide Metrology and its Applications (Applied Radiation and Isotopes). - Amsterdam : Elsevier BV. - 1872-9800 .- 0969-8043. ; 64:10-11, s. 1253-1259
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Konferensbidrag (refereegranskat)abstract
- A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (Sr-90, Pb-210(Po-210), Ra-226, Pu-239, Pu-240 Pu-241). Less frequently reported radionuclides (Tc-99, I-129, Th-228, Th-230 and Np-217) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units.
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| 2. |
- Rusydi, A., et al.
(författare)
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Metal-insulator transition in manganites: Changes in optical conductivity up to 22 eV
- 2008
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Ingår i: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969. ; 78:12, s. 125110 (art. no.)-
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Tidskriftsartikel (refereegranskat)abstract
- The electronic response of doped manganites at the transition from the paramagnetic insulating to the ferromagnetic metallic state in La(1-x)Ca(x)MnO(3) for x=0.3 and 0.2 was investigated by dc conductivity, ellipsometry, and vacuum ultraviolet reflectance for energies between 0 and 22 eV. A stabilized Kramers-Kronig transformation yields the optical conductivity and reveals changes in the optical spectral weight up to 22 eV at the metal-to-insulator transition. In the observed energy range, the spectral weight is conserved within 0.3%. The redistribution of spectral weight in this surprisingly broad energy range has important ramifications for the effective low-energy physics. We discuss the importance of the charge-transfer, Coulomb on-site, Jahn-Teller, and long-range Coulomb screening effects to the electronic structure.
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| 3. |
- Pham, M. K., et al.
(författare)
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A new Certified Reference Material for radionuclides in Irish sea sediment (IAEA-385)
- 2008
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Ingår i: APPLIED RADIATION AND ISOTOPES. - : Elsevier BV. - 1872-9800 .- 0969-8043. ; 66:11, s. 1711-1717
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Konferensbidrag (refereegranskat)abstract
- A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides (K-40, Cs-137, Ra-226, Ra-228, Th-230, Th-232, U-234, U-238, Pu-238, Pu239+240 and Am-241) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides (Sr-90, Pb-210(Po-210), U-235, Pu-239, Pu-240 and Pu-241). Results for less frequently reported radionuclides (Co-60, Tc-99, Cs-134, Eu-155, Ra-224 and Np-239) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes. (C) 2008 IAEA. Published by Elsevier Ltd. All rights reserved.
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| 4. |
- Povinec, Pavel, et al.
(författare)
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Reference material for radionuclides in sediment. IAEA-384 (Fangataufa lagoon sediment).
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - Dordrecht : Springer. - 0236-5731 .- 1588-2780. ; 273:2, s. 383-393
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Tidskriftsartikel (refereegranskat)abstract
- A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units.
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| 5. |
- Hultquist, Gunnar, et al.
(författare)
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Effects of O-2 dissociation on a porous platinum coating in the thermal oxidation of GaAs
- 2006
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 153:2, s. G182-G186
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Tidskriftsartikel (refereegranskat)abstract
- A 20-30-nm-thick porous Pt layer has been sputter-coated on a portion of a GaAs sample and subsequently the sample was oxidized at 500 degrees C in O-16(2) followed by O-18-enriched O-2. The oxide formed was characterized by Auger electron spectroscopy, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy, all with a lateral resolution of about 100 mu m. Away from the Pt area, a mm-ranged gradually decreasing degree of As oxidation was observed in the outermost oxide layer. In the Pt area, Ga was preferentially oxidized at the oxide/substrate interface producing a five to seven times thicker oxide than in an area without the influence of Pt. A strongly enhanced dissociation rate of O-2 on Pt particles and a subsequent O spillover to adjacent oxide explain the experimental observations. The mm-ranged spillover is believed to take place via fast lateral surface diffusion and results in the observed variation of oxidized As at the gas/oxide interface. In the Pt area, a high concentration gradient of dissociated oxygen across the oxide layer supplies a high flux of dissociated oxygen to the GaAs substrate where Ga is preferentially oxidized. The results clearly demonstrate that both a surface reaction and solid-state diffusion influence the oxidation rate. A localized high effective oxygen (O) activity that spills over to a nearby oxide area is believed to be a general phenomenon that is operating in oxides where a dissociating element such as Pt is present at O-2/oxide interfaces.
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