Sample records for 256no 270sg 271hs

  1. The possible existence of Hs in nature from a geochemical point of view

    CERN Document Server

    Ivanov, A V


    A hypothesis of the existence of a long-lived isotope 271Hs in natural molybdenites and osmirides is considered from a geochemical point of view. It is shown that the presence of Hs in these minerals can be explained only by making an additional ad hoc assumption on the existence of an isobaric pair of 271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements of U, Pb, Kr, Xe, and Zr isotopic shifts.

  2. [Anti-toxoplasma antibodies in bovine serums in Jaboticabal County; São Paulo, Brazil]. (United States)

    Costa, A J; Avila, F A; Kassai, N; Paulillo, A C; Barbosa da Silva, M; Galesco, H


    Sera of 204 cows in Jaboticabal, S.P., Brazil were examined by indirect immunofluorescent test for detecting anti-Toxoplasma antibody. Assuming titers from 1:64 as indicative of toxoplasmic infection it was observed 32.3% of positive reactions. The antibody titers even to 1:256 represented 7.8% of the reacting animals. The serological titers varied from 1:64 to 1:256. No clinical story could be correlated with the reacting animals and no isolation was performed.

  3. Decay properties of nuclei close to Z = 108 and N = 162

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, Jan


    The goal of the research conducted in the frame of this thesis was to investigate the decay properties of the nuclides {sup 269-271}Hs and their daughters using an improved chemical separation and detection system. Shell stabilization was predicted in the region around Z=108 and N=162 in calculations, taking into account possible higher orders of deformations of the nuclei. The nucleus {sup 270}Hs with a closed proton and a closed neutron deformed shell, was predicted to be ''deformed doubly magic''. Nuclei around {sup 270}Hs can be produced only via fusion reactions at picobarn levels, resulting in a production rates of few atoms per day. Investigating short-lived nuclei using rapid chemical separation and subsequent on-line detection methods provides an independent and alternative means to electromagnetic on-line separators. Chemical separation of Hs in the form of HsO{sub 4} provides an excellent tool to study the formation reactions and nuclear structure in this region of the chart of nuclides due to a high overall efficiency and a very high purification factor. The goal was accomplished, as element 108, hassium, was produced in the reaction {sup 248}Cm({sup 26}Mg,xn){sup 274-x}Hs and chemically isolated. After gas phase separation of HsO{sub 4}, 26 genetically linked decay chains have been observed. These were attributed to decays of three different Hs isotopes produced in the 3-5n evaporation channels. The known decay chain of {sup 269}Hs, the 5n evaporation product, serves as an anchor point, thus allowing the unambiguous assignment of the observed decay chains to the 5n, 4n, and 3n channels, respectively. Decay properties of five nuclei have been unambiguously established for the first time, including the one for the the doubly-magic nuclide {sup 270}Hs. This hassium isotope is the next doubly magic nucleus after the well known {sup 208}Pb and the first experimentally observed even-even nucleus on the predicted N=162 neutron shell. The

  4. Dynamical collective potential energy landscape: its impact on the competition between fusion and quasi-fission in a heavy fusing system

    CERN Document Server

    Díaz-Torres, A


    A realistic microscopically-based quantum approach to the competition between fusion and quasi-fission in a heavy fusing system is applied to several reactions leading to $^{256}$No. Fusion and quasi-fission are described in terms of a diffusion process of nuclear shapes through a dynamical collective potential energy landscape which is initially diabatic and gradually becomes adiabatic. The microscopic ingredients of the theory are obtained with a realistic two-center shell model based on Woods-Saxon potentials. The results indicate that (i) the diabatic effects play a very important role in the onset of fusion hindrance for heavy systems, and (ii) very asymmetric reactions induced by closed shell nuclei seem to be the best suited to synthesize the heaviest compound nuclei.

  5. Theory of competition between fusion and quasi-fission in a heavy fusing system

    CERN Document Server

    Díaz-Torres, A


    A theory of the competition between fusion and quasi-fission in a heavy fusing system is proposed, which is based on a master equation and the two-center shell model. Fusion and quasi-fission arise from a diffusion process in an ensemble of nuclear shapes evolving towards the thermal equilibrium. The master equation describes the diffusion of the nuclear shapes due to quantum and thermal fluctuations. Other crucial physical effects like dissipation, ground-state shell effects, diabatic effects and rotational effects are also incorporated into the theory. The fusing system moves in a dynamical (time-dependent) collective potential energy surface which is initially diabatic and gradually becomes adiabatic. The microscopic ingredients of the theory are obtained with a realistic two-center shell model based on Woods-Saxon potentials. Numerical calculations for several reactions leading to $^{256}$No are discussed. Among other important conclusions, the results indicate that (i) the diabatic effects play a very im...

  6. Systematic study of probable projectile-target combinations for the synthesis of the superheavy nucleus 302120 (United States)

    Santhosh, K. P.; Safoora, V.


    Probable projectile-target combinations for the synthesis of the superheavy element 302120 have been studied taking the Coulomb and proximity potential as the interaction barrier. The probabilities of the compound nucleus formation PCN for the projectile-target combinations found in the cold reaction valley of 302120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion, and evaporation residue cross sections for the reactions of all probable projectile-target combinations so as to predict the most promising projectile-target combinations for the synthesis of the superheavy element 302120 in heavy-ion fusion reactions. The calculated fusion and evaporation cross sections for the more asymmetric ("hotter") projectile-target combination is found to be higher than the less asymmetric ("colder") combination. It can be seen from the nature of the quasifission barrier height, mass asymmetry, the probability of compound nucleus formation, survival probability, and excitation energy, the systems 44Ar+258No , 46Ar+256No , 48Ca+254Fm , 50Ca+252Fm , 54Ti+248Cf , and 58Cr+244Cm in deep region I of the cold reaction valley and the systems 62Fe+240Pu , 64Fe+238Pu , 68Ni+234U , 70Ni+232U , 72Ni+230U , and 74Zn+228Th in the other cold valleys are identified as the better projectile-target combinations for the synthesis of 302120. Our predictions on the synthesis of 302120 superheavy nuclei using the combinations 54Cr+248Cm , 58Fe+244Pu , 64Ni+238U , and 50Ti+249Cf are compared with available experimental data and other theoretical predictions.

  7. Alterações patológicas do sistema genital de cutias (Dasyprocta aguti Linnaeus, 1758 fêmeas criadas em cativeiro

    Directory of Open Access Journals (Sweden)

    Jael S. Batista

    Full Text Available Resumo: Este artigo apresenta relatos de sete distintas patologias de origem reprodutiva ainda não descritas em cutias (Dasyprocta aguti Linnaeus, 1758 fêmeas, que afetaram a fertilidade ou resultaram na morte do animal. Descreveu-se a natureza, a localização e a frequência das alterações patológicas macroscópicas e histológicas dos órgãos que compõem o sistema reprodutivo de cutias fêmeas, criadas sob condições de cativeiro no semiárido do Brasil. Foram avaliados através do exame anatomopatológico o aparelho reprodutivo de trinta e nove cutias mortas naturalmente e encaminhadas ao Laboratório de Patologia Veterinária, no período de fevereiro de 2010 a maio de 2015. Destas, constatou-se alterações patológicas no sistema reprodutivo de 10 (25,6 %. No total, 13 alterações foram observadas, sendo que, em alguns animais haviam a coexistência de mais de uma alteração. Assim, as alterações patológicas encontradas foram: endometrite (n=4; 30,8%, piometra (n=3; 23%, retenção de placenta (n=2; 15,4%, maceração fetal (n=1; 7,7%, mumificação fetal (n=1; 7,7%, parto distócico (n=1; 7,7% e ovários afuncionais (n=1; 7,7%.

  8. Is baby-friendly breastfeeding support in maternity hospitals associated with breastfeeding satisfaction among Japanese mothers? (United States)

    Hongo, Hiroko; Nanishi, Keiko; Shibanuma, Akira; Jimba, Masamine


    While the World Health Organization's Baby-Friendly Hospital Initiative has increased breastfeeding duration and exclusivity, a survey found that only 8.5 % of maternity hospitals in 31 developed countries could be designated baby-friendly. Baby-friendly breastfeeding support is sometimes criticized as mother unfriendly. This study examined whether baby-friendly breastfeeding support was associated with breastfeeding satisfaction, duration, and exclusivity among Japanese mothers. In this cross-sectional study, 601 breastfeeding Japanese mothers completed questionnaires at their infants' 4-month health checkups at two wards in Yokohama, Japan; 363 were included in the analysis. Baby-friendly breastfeeding support was measured based on the WHO's "Ten Steps to Successful Breastfeeding." We measured satisfaction using two subscales of the Japanese version of the Maternal Breastfeeding Evaluation Scale. The association of baby-friendly support with maternal satisfaction was assessed using multiple linear regression, while the prevalence ratios (PRs) for breastfeeding were estimated using Poisson regression. Mothers were stratified by prepartum exclusive breastfeeding intention (yes, n = 256; no, n = 107). Mothers who experienced early skin-to-skin contact with their infants were more likely to report breastfeeding satisfaction than those who did not. Among mothers without exclusive breastfeeding intention, those who were encouraged to feed on demand were more likely to be breastfeeding without formula at 1 month (PR 2.66 [95 % CI 1.32, 5.36]) and to perceive breastfeeding as beneficial for their baby (regression coefficient = 3.14 [95 % CI 0.11, 6.17]) than those who were not so encouraged. Breastfeeding satisfaction was a useful measure of breastfeeding outcome. Early skin-to-skin contact and encouragement to feed on demand in the hospital facilitate breastfeeding satisfaction.