28 research outputs found

    The socioeconomic impact of tuberculosis on children and adolescents : a scoping review and conceptual framework

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    Background: Tuberculosis (TB) has been repeatedly shown to have socioeconomic impacts in both individual-level and ecological studies; however, much less is known about this effect among children and adolescents and the extent to which being affected by TB during childhood and adolescence can have life-course implications. This paper describes the results of the development of a conceptual framework and scoping review to review the evidence on the short- and long-term socioeconomic impact of tuberculosis on children and adolescents. Objectives: To increase knowledge of the socioeconomic impact of TB on children and adolescents. Methods: We developed a conceptual framework of the socioeconomic impact of TB on children and adolescents, and used scoping review methods to search for evidence supporting or disproving it. We searched four academic databases from 1 January 1990 to 6 April 2021 and conducted targeted searches of grey literature. We extracted data using a standard form and analysed data thematically. Results: Thirty-six studies (29 qualitative, five quantitative and two mixed methods studies) were included in the review. Overall, the evidence supported the conceptual framework, suggesting a severe socioeconomic impact of TB on children and adolescents through all the postulated pathways. Effects ranged from impoverishment, stigma, and family separation, to effects on nutrition and missed education opportunities. TB did not seem to exert a different socioeconomic impact when directly or indirectly affecting children/adolescents, suggesting that TB can affect this group even when they are not affected by the disease. No study provided sufficient follow-up to observe the long-term socioeconomic effect of TB in this age group. Conclusion: The evidence gathered in this review reinforces our understanding of the impact of TB on children and adolescents and highlights the importance of considering effects during the entire life course. Both ad-hoc and sustainable social protection measures and strategies are essential to mitigate the socioeconomic consequences of TB among children and adolescents.publishedVersionPeer reviewe

    A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes

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    © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the 233U(n, γ) cross-section at the n_TOF facility at CERN, where it was coupled to the n_TOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.Peer reviewe

    Neutron induced fission cross section measurements of 240

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    Accurate neutron induced fission cross section of 240Pu and 242Pu are required in view of making nuclear technology safer and more efficient to meet the upcoming needs for the future generation of nuclear power plants (GEN-IV). The probability for a neutron to induce such reactions figures in the NEA Nuclear Data High Priority Request List [1]. A measurement campaign to determine neutron induced fission cross sections of 240Pu and 242Pu at 2.51 MeV and 14.83 MeV has been carried out at the 3.7 MV Van De Graaff linear accelerator at Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig. Two identical Frisch Grid fission chambers, housing back to back a 238U and a APu target (A = 240 or A = 242), were employed to detect the total fission yield. The targets were molecular plated on 0.25 mm aluminium foils kept at ground potential and the employed gas was P10. The neutron fluence was measured with the proton recoil telescope (T1), which is the German primary standard for neutron fluence measurements. The two measurements were related using a De Pangher long counter and the charge as monitors. The experimental results have an average uncertainty of 3–4% at 2.51 MeV and for 6–8% at 14.81 MeV and have been compared to the data available in literature

    Use of active scintillating targets in nuclear physics experiments - Measurement of spontaneous fission

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    A novel detector has been used, in order to perform measurements of spontaneous fission to α-decay ratios for 240Pu, 242Pu and 252Cf isotopes. The detectors are based on the well-known technique of liquid scintillating counting. The principle and advantages of the use of such detectors in nuclear physics is discussed. The application to the characterization of spontaneous fission is described and it is demonstrated that highly precise measurements are possible, and that the main limit is due to the isotopic content knowledge of the measured samples

    Use of active scintillating targets in nuclear physics experiments - Measurement of spontaneous fission

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    A novel detector has been used, in order to perform measurements of spontaneous fission to α-decay ratios for 240Pu, 242Pu and 252Cf isotopes. The detectors are based on the well-known technique of liquid scintillating counting. The principle and advantages of the use of such detectors in nuclear physics is discussed. The application to the characterization of spontaneous fission is described and it is demonstrated that highly precise measurements are possible, and that the main limit is due to the isotopic content knowledge of the measured samples

    High-precision spontaneous fission branching-ratio measurements for 240,242Pu^{240,242}\mathrm{Pu} and 252Cf^{252}\mathrm{Cf} isotopes

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    International audienceWe report here very precise measurements of the spontaneous fission branching ratio for the Pu240,242 and Cf252 isotopes, performed with a new kind of active scintillating target. It is shown that the method itself leads to unprecedentedly small uncertainties, and that these uncertainties are negligible compared to uncertainties on the isotopic content of the sample. Besides this capability we discuss the possibility to use this kind of detector for the systematic study of charged particle radioactivity, i.e., spontaneous fission, α decay, and heavy-ion radioactivity

    Prompt fission gamma-ray spectrum characteristics from Pu-240(sf) and Pu-242(sf)

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    In this paper we present first results for prompt fission gamma-ray spectra (PFGS) characteristics from the spontaneous fission (sf) of Pu-240 and Pu-242. For Pu-242(sf) we obtained, after proper unfolding of the detector response, an average energy per photon (epsilon) over bar (gamma) = (0.843 +/- 0.012) MeV, an average multiplicity (M) over bar (gamma) = (6.72 +/- 0.07), and an average total gamma-ray energy release per fission (E) over bar (gamma,tot) = (5.66 +/- 0.06) MeV. The Pu-240(sf) emission spectrum was obtained by applying a so-called detector-response transformation function determined from the Pu-242 spectrum measured in exactly the same geometry. The results are an average energy per photon (epsilon) over bar = (0.80 +/- 0.07) MeV, the average multiplicity (M) over bar (gamma) = (8.2 +/- 0.4), and an average total gamma-ray energy release per fission (E) over bar (gamma,tot) = (6.6 +/- 0.5) MeV. The PFGS characteristics for Pu-242(sf) are in very good agreement with those from thermal-neutron-induced fission on Pu-241 and scales well with the corresponding prompt neutron multiplicity. Our results in the case of Pu-240(sf), although drawn from a limited number of events, show a significantly enhanced average multiplicity and average total energy, but may be understood from a different fragment yield distribution in Pu-240(sf) compared to that of Pu-242(sf)

    Towards high accurate neutron-induced fission cross sections of

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    Fast spectrum neutron-induced fission cross sections of transuranic isotopes are being of special demand in order to provide accurate data for the new GEN-IV nuclear power plants. To minimize the uncertainties on these measurements accurate data on spontaneous fission half-lives and detector efficiencies are a key point. High α-active actinides need special attention since the misinterpretation of detector signals can lead to low efficiency values or underestimation in fission fragment detection. In that context, 240,242Pu isotopes have been studied by means of a Twin Frisch-Grid Ionization Chamber (TFGIC) for measurements of their neutron-induced fission cross section. Gases with different drift velocities have been used, namely P10 and CH4. The detector efficiencies for both samples have been determined and improved spontaneous fission half-life values were obtained
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