513 research outputs found

    Analysis of natural neutron flux in a seismically active zone

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    International audienceIn a seismically active zone in the near Almaty area (Kazakhstan) since 1996 observations of variations of a natural neutron flux have been conducted. Sometimes the neutron flux rises sharply within the one-hour interval in comparison with the background. It occurs on the eve of activation of seismic processes. Increase of the neutron flux level had taken place from 1 h to 10 days prior to earthquakes. It is also indicated a tendency of growth of the anomaly level in accordance with the growth of energetic class of the subsequent earthquake. A character of connection between the neutron flux and earthquakes is still not clear. It is proposed that the neutron flux anomalies caused by variations of cosmic radiation intensity under action of fluxes of solar material, which is burst into interplanetary space (solar wind) during solar flares. Energy of the solar wind transferred to Earth puts into action a trigger mechanism of the process of initiation of earthquakes at those places where conditions have already been prepared for them. The neutron flux anomalies can be used as substantial additional information for classical geophysical methods of short-term earthquake prediction

    Production of Λ6^{6}_{\Lambda}H and Λ7^{7}_{\Lambda}H with the (Kstop−^{-}_{stop},π+\pi^+) reaction

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    The production of neutron rich Λ\Lambda-hypernuclei via the (Ks−topK^-_stop,π+\pi^+) reaction has been studied using data collected with the FINUDA spectrometer at the DAΦ\PhiNE ϕ\phi-factory (LNF). The analysis of the inclusive π+\pi^+ momentum spectra is presented and an upper limit for the production of Λ6^6_\LambdaH and Λ7^7_\LambdaH from 6^6Li and 7^7Li, is assessed for the first time.Comment: 11 pages, 3 figures. Accepted for publication in PL

    A study of the proton spectra following the capture of K−K^- in 6^6Li and 12^{12}C with FINUDA

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    Momenta spectra of protons emitted following the capture of K−K^- in 6^6Li and 12^{12}C have been measured with 1% resolution. The 12^{12}C spectrum is smooth whereas for 6^6Li a well defined peak appears at about 500 MeV/cc. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a Kˉ\bar K-nuclear state. The peak is correlated with a π−\pi^- coming from Σ−\Sigma^- decay in flight, selected by setting momenta larger than 275 MeV/cc. The Σ−\Sigma^- could be produced, together with a 500 MeV/cc proton, by the capture of a K−K^- in a deuteron-cluster substructure of the 6^6Li nucleus. The capture rate for such a reaction is (1.62\pm 0.23_{stat} ^{+0.71}_{-0.44}(sys))%/K^-_{stop}, in agreement with the existing observations on 4^4He targets and with the hypothesis that the 6^6Li nucleus can be interpreted as a (d+α)(d+\alpha) cluster.Comment: 21 pages, 10 figures. Accepted for publication in NP

    Correlated Λd\Lambda d pairs from the Kstop−A→ΛdA′K^{-}_{stop} A \to \Lambda d A' reaction

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    Correlated Λd\Lambda d pairs emitted after the absorption of negative kaons at rest Kstop−A→ΛdA′K^{-}_{stop}A\to \Lambda d A' in light nuclei 6Li^6Li and 12C^{12}C are studied. Λ\Lambda-hyperons and deuterons are found to be preferentially emitted in opposite directions. The Λd\Lambda d invariant mass spectrum of 6Li^6Li shows a bump whose mass is 3251±\pm6 MeV/c2^2. The bump mass (binding energy), width and yield are reported. The appearance of a bump is discussed in the realm of the [Kˉ3N\bar{K}3N] clustering process in nuclei. The experiment was performed with the FINUDA spectrometer at DAΦ\PhiNE (LNF).Comment: 13 pages, 5 figures, accepted for publication in Phys. Lett.

    Prospects for the use of a <i>Bacillus subtilis</i> metabolites-based feed additive in dairy farming

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    Laboratory and field experiment on use of the feed additive based on Bacillus subtilis endo- and exometabolites for the cows in different physiological periods are described in the paper. The feed additive impact on main body systems of the tested cows (n = 30), milk production parameters, growth rate of the calves (n = 18) born to the said cows were examined. The feed additive was added to the diets for the cows of test groups, 15 g per cow. The feed additive was found to have a positive effect on immunohematological and metabolic processes in postpartum cows. Neutrophils’ phagocytic activity increased by 12.5% and 14.6% in the animals of test group 1 and test group 2, respectively, as compared to that one in control animals (42.8 ± 1.9%). Neutrophil absorbency increased by 2.5 times, 3.2 times and 2.1 times in the animals of test group 1, test group 2 and control group, respectively. The proportion of T-lymphocytes in blood of animals in test group 1 and test group 2 was 44.5 and 48.9%, respectively, proportion of T-lymphocytes in blood of control animals equaled to 37.5%. Trend for increase in total protein concentration in cow sera owing to increase in albumin fraction was observed in postpartum period: it was 72.91 ± 3.45 g/l in test group 1; 75.54 ± 4.12 g/l in test group 2; 70.95 ± 4.25 g/l in control group. Average daily milk yield in cows of test group 1, test group 2 and control group for the 150 days of lactation was 24.50 ± 1.86 kg; 25.33 ± 1.45 kg and 22.75 ± 4.41 kg, respectively. Higher growth rate was reported for the calves born to the cows received the diet supplemented with the said feed additive. Heifers of test group 1 and test group 2 have reached body weight of 193.51 ± 5.76 and 195.33 ± 3.76 kg and in control group – of 187.33 ± 4.98 kg within 6 months. Feed additive based on endo- and exometabolites of Bacillus subtilis is recommended for cow diets for highly productive dairy herd creation and food-producing animal welfare maintenance
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