443 research outputs found

    Dynamique des populations de Bulinus truncatus rohlfsi Clessin, 1886, dans le barrage de Dyoro en zone nord soudanienne du Burkina Faso

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    Le suivi bi-hebdomadaire des effectifs de #Bulinus truncatus rohlfi et les mesures des paramètres physico-chimiques (pluviométrie, température, pH et conductivité) montrent que la dynamique des populations de cette espèce est dépendante de l'évolution de la température de l'eau. Cette donnée pourrait renforcer les méthodes de lutte contre ce mollusque hôte intermédiaire de #Schistosoma haematobium, parasite de la bilharziose urinaire au Burkina Faso

    Background suppression in massive TeO2_2 bolometers with Neganov-Luke amplified light detectors

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    Bolometric detectors are excellent devices for the investigation of neutrinoless double-beta decay (0νββ\nu\beta\beta). The observation of such decay would demonstrate the violation of lepton number, and at the same time it would necessarily imply that neutrinos have a Majorana character. The sensitivity of cryogenic detectors based on TeO2_2 is strongly limited by the alpha background in the region of interest for the 0νββ\nu\beta\beta of 130^{130}Te. It has been demonstrated that particle discrimination in TeO2_2 bolometers is possible measuring the Cherenkov light produced by particle interactions. However an event-by-event discrimination with NTD-based light detectors has to be demonstrated. We will discuss the performance of a highly-sensitive light detector exploiting the Neganov-Luke effect for signal amplification. The detector, being operated with NTD-thermistor and coupled to a 750 g TeO2_2 crystal, shows the ability for an event-by-event identification of electron/gamma and alpha particles. The extremely low detector baseline noise, RMS 19 eV, demonstrates the possibility to enhance the sensitivity of TeO2_2-based 0νββ\nu\beta\beta experiment to an unprecedented level

    Final results of an experiment to search for 2beta processes in zinc and tungsten with the help of radiopure ZnWO4 crystal scintillators

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    A search for the double beta decay of zinc and tungsten isotopes has been performed with the help of radiopure ZnWO4 crystal scintillators (0.1-0.7 kg) at the Gran Sasso National Laboratories of the INFN. The total exposure of the low background measurements is 0.529 kg yr. New improved half-life limits on the double beta decay modes of 64Zn, 70Zn, 180W, and 186W have been established at the level of 10^{18}-10^{21} yr. In particular, limits on double electron capture and electron capture with positron emission in 64Zn have been set: T_{1/2}(2\nu 2K) > 1.1 10^{19} yr, T_{1/2} (0\nu 2\epsilon) > 3.2 10^{20} yr, T_{1/2} (2\nu \epsilon \beta^+) > 9.4 10^{20} yr, and T_{1/2} (0\nu \epsilon \beta^+) > 8.5 10^{20} yr, all at 90% C.L. Resonant neutrinoless double electron capture in 180W has been restricted on the level of T_{1/2} (0\nu 2\epsilon) > 1.3 10^{18} yr. A new half-life limit on alpha transition of 183W to the metastable excited level 1/2^- 375 keV of 179Hf has been established: T_{1/2} > 6.7 10^{20} yr.Comment: This is an author-created, un-copyedited version of an article published in J. Phys. G: Nucl. Part. Phys. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at doi: 10.1088/0954-3899/38/11/11510

    Rejection of randomly coinciding events in Li2_2100^{100}MoO4_4 scintillating bolometers using light detectors based on the Neganov-Luke effect

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    Random coincidences of nuclear events can be one of the main background sources in low-temperature calorimetric experiments looking for neutrinoless double-beta decay, especially in those searches based on scintillating bolometers embedding the promising double-beta candidate 100^{100}Mo, because of the relatively short half-life of the two-neutrino double-beta decay of this nucleus. We show in this work that randomly coinciding events of the two-neutrino double decay of 100^{100}Mo in enriched Li2_2100^{100}MoO4_4 detectors can be effectively discriminated by pulse-shape analysis in the light channel if the scintillating bolometer is provided with a Neganov-Luke light detector, which can improve the signal-to-noise ratio by a large factor, assumed here at the level of 750\sim 750 on the basis of preliminary experimental results obtained with these devices. The achieved pile-up rejection efficiency results in a very low contribution, of the order of 6×105\sim 6\times10^{-5} counts/(keV\cdotkg\cdoty), to the background counting rate in the region of interest for a large volume (90\sim 90 cm3^3) Li2_2100^{100}MoO4_4 detector. This background level is very encouraging in view of a possible use of the Li2_2100^{100}MoO4_4 solution for a bolometric tonne-scale next-generation experiment as that proposed in the CUPID project

    Search for double beta decay of 136^{136}Ce and 138^{138}Ce with HPGe gamma detector

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    Search for double β\beta decay of 136^{136}Ce and 138^{138}Ce was realized with 732 g of deeply purified cerium oxide sample measured over 1900 h with the help of an ultra-low background HPGe γ\gamma detector with a volume of 465 cm3^3 at the STELLA facility of the Gran Sasso National Laboratories of the INFN (Italy). New improved half-life limits on double beta processes in the cerium isotopes were set at the level of limT1/210171018\lim T_{1/2}\sim 10^{17}-10^{18}~yr; many of them are even two orders of magnitude larger than the best previous results.Comment: 21 pages, 6 figures, 3 tables; version accepted for publication on Nucl. Phys.

    Political and legal aspects of the information warfare

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    This article describes the technological features of information warfare and possible lawful mechanisms to counter information attacks. The aim of the article is to analyse the political and legal features of information warfare. The tactics of the aggressor state’s behaviour in a hybrid war was substantiated using the case of the information war between Russia and Ukraine. The channels of information dissemination, which are most often used for disintegration and disinformation purposes, were studied. Problematic issues of the domestic public space that most often appear in the perspective of disinformation attacks on the Internet are determined: the activities of the Armed Forces of Ukraine, cooperation between Ukraine and the EU, reforms in Ukrainian society, temporarily occupied territories and annexed Crimea, corruption in Ukraine. The tactics of confrontation between countries in the information space was analysed — attempts to establish their “security belt” from other actors in international relations and to maintain their own dominant influence in certain regions by spreading misinformation. Promising areas of further research will be the analysis of the peculiarities of the national legal systems’ development in order to counter misinformation in the context of the continuous development of democracy in the world

    First test of an enriched 116^{116}CdWO4_4 scintillating bolometer for neutrinoless double-beta-decay searches

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    For the first time, a cadmium tungstate crystal scintillator enriched in 116^{116}Cd has been succesfully tested as a scintillating bolometer. The measurement was performed above ground at a temperature of 18 mK. The crystal mass was 34.5 g and the enrichment level ~82 %. Despite a substantial pile-up effect due to above-ground operation, the detector demonstrated a high energy resolution (2-7 keV FWHM in 0.2-2.6 MeV γ\gamma energy range), a powerful particle identification capability and a high level of internal radiopurity. These results prove that cadmium tungstate is an extremely promising detector material for a next-generation neutrinoless double-beta decay bolometric experiment, like that proposed in the CUPID project (CUORE Upgrade with Particle IDentification)

    First search for double-beta decay of 184Os and 192Os

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    A search for double-beta decay of osmium has been realized for the first time with the help of an ultra-low background HPGe gamma detector at the underground Gran Sasso National Laboratories of the INFN (Italy). After 2741 h of data taking with a 173 g ultra-pure osmium sample limits on double-beta processes in 184Os have been established at the level of T_{1/2} about 10^{14}-10^{17} yr. Possible resonant double-electron captures in 184Os were searched for with a sensitivity T_{1/2} about 10^{16} yr. A half-life limit T_{1/2} > 5.3 10^{19} yr was set for the double-beta decay of 192Os to the first excited level of 192Pt. The radiopurity of the osmium sample has been investigated and radionuclides 137Cs, 185Os and 207Bi were detected in the sample, while activities of 40K, 60Co, 226Ra and 232Th were limited at the mBq/kg level.Comment: 12 pages, 7 figures, 2 table
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