Institution
National Nuclear Energy Commission
Government•Rio de Janeiro, Brazil•
About: National Nuclear Energy Commission is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Dosimetry & Laser. The organization has 3816 authors who have published 4694 publications receiving 59951 citations.
Topics: Dosimetry, Laser, Neutron, Corrosion, Monte Carlo method
Papers published on a yearly basis
Papers
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01 Dec 2007-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, a non toxicity and biocompatible hydrogel system with potential ability in biotechnology based on membranes of polyethylene glycol (PEG 300 and 400) and chitosan were prepared under ultraviolet light (UV) and γ-radiation curing, at room temperature.
Abstract: In order to develop a non toxicity and biocompatible hydrogel system with potential ability in biotechnology based on membranes of polyethylene glycol (PEG 300 and 400) and chitosan were prepared under ultraviolet light (UV) and γ-radiation curing, at room temperature. The hydrogels were characterized by FTIR spectroscopic, UV absorption spectroscopy, thermal analysis and scanning electronic microscopy. The swelling behaviors were investigated in terms of time of swelling, irradiation time, and pH. The hydrogel with PEG 300 showed unusual swelling behavior.
32 citations
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TL;DR: In this paper, the authors used the laser ablation sector field inductively coupled plasma mass spectrometry (LA-SF-ICP-MS) technique for the determination of uranium isotopic composition in a highly enriched uranium sample.
Abstract: This work describes the utilization of the laser ablation sector field inductively coupled plasma mass spectrometry (LA-SF-ICP-MS) technique for the determination of uranium isotopic composition in a highly enriched uranium sample. The measurements were performed on a continuous ablation with low energy density and defocusing, which demonstrated to be the optimum to reach the best signal stability. The measurements were improved by adjusting the following parameters: RF power, laser beam diameter, defocusing of laser beam, laser energy, laser energy density, auxiliary gas and sample gas. The 235U/238U isotope ratio with its respective uncertainty was 16.36 ± 0.15 and its precision was 1.12 % relative standard deviation. The uncertainties were estimated following the ISO GUM, with a confidence level of 95.45 % (k = 2.00). When compared the isotope abundances to the Round Robin Exercise Number 3’s average results a difference of 0.46 % has been found and when compared to supplier’s value, the difference was 0.41 %. The results presented by the measurements revealed that the LA-ICP-MS technique offers a rapid and accurate alternative to measure uranium isotope ratios without any sample preparation, since it allows carrying out the measurements straight on the sample. Moreover, it preserves the testimony—very important for safeguards and nuclear forensics purposes.
32 citations
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TL;DR: In this paper, from simple quark model arguments and assuming a quadratic η − η mixing, the radiative decays of the vector and pseudoscalar mesons were predicted.
32 citations
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TL;DR: In this article, a time efficient optical model is proposed for GATE simulation of a LYSO scintillation matrix coupled to a photomultiplier to avoid the excessively long computation time when activating the optical processes in GATE.
Abstract: A time efficient optical model is proposed for GATE simulation of a LYSO scintillation matrix coupled to a photomultiplier. The purpose is to avoid the excessively long computation time when activating the optical processes in GATE. The usefulness of the model is demonstrated by comparing the simulated and experimental energy spectra obtained with the dual planar head equipment for dosimetry with a positron emission tomograph (DoPET). The procedure to apply the model is divided in two steps. Firstly, a simplified simulation of a single crystal element of DoPET is used to fit an analytic function that models the optical attenuation inside the crystal. In a second step, the model is employed to calculate the influence of this attenuation in the energy registered by the tomograph. The use of the proposed optical model is around three orders of magnitude faster than a GATE simulation with optical processes enabled. A good agreement was found between the experimental and simulated data using the optical model. The results indicate that optical interactions inside the crystal elements play an important role on the energy resolution and induce a considerable degradation of the spectra information acquired by DoPET. Finally, the same approach employed by the proposed optical model could be useful to simulate a scintillation matrix coupled to a photomultiplier using single or dual readout scheme.
32 citations
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TL;DR: In this paper, the influence of bioglass additions on the sintering and mechanical properties of yttria-stabilized zirconia ceramics, Y-TZP, was evaluated.
32 citations
Authors
Showing all 3838 results
Name | H-index | Papers | Citations |
---|---|---|---|
Giorgio Parisi | 108 | 941 | 60746 |
Sergio Ferrara | 105 | 726 | 44507 |
Richard Wilson | 70 | 809 | 21477 |
Eliana B. Souto | 66 | 447 | 15706 |
Andrea Saltelli | 65 | 184 | 31540 |
Fausto Croce | 51 | 162 | 11753 |
Sílvia M. Rocha | 42 | 163 | 4934 |
Marcos Duarte | 41 | 122 | 5855 |
Luiz Gustavo Cançado | 41 | 106 | 13155 |
Ruggero Caminiti | 41 | 267 | 7296 |
Francesco Romanelli | 40 | 236 | 5756 |
Mario Molinaro | 39 | 111 | 5923 |
Giovanna Cenacchi | 38 | 217 | 4948 |
Claudio Pellegrini | 38 | 235 | 5885 |
Maria Manuela Silva | 37 | 324 | 5258 |