| 1. |
- Mach, Henryk, et al.
(författare)
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The single-particle and collective features in the nuclei just above Sn-132
- 2007
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1213-1218
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Tidskriftsartikel (refereegranskat)abstract
- The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sn-134, Sn-135 and Sn-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2(+) state in Sb-135 and its E2 transition to the lower-lying 5/2(+) state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing.
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| 2. |
- Klimkiewicz, A., et al.
(författare)
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Pygmy Dipole Strength in Exotic Nuclei and the Equation of State
- 2009
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Ingår i: AIP Conference Proceedings. - 1551-7616 .- 0094-243X. ; 1165, s. 181-184 461
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Konferensbidrag (refereegranskat)abstract
- A concentration of dipole strength at energies below the giant dipole resonance was observed in neutron-rich nuclei around Sn-132 in an experiment using the FRS-LAND setup. This so-called "pygmy" dipole strength can be related to the parameters of the symmetry energy and to the neutron skin thickness on the grounds of a relativistic quasiparticle random-phase approximation. Using this ansatz and the experimental findings for Sn-130 and 132 Sri, we derive a value of the symmetry energy pressure of (p) over bar (0) = 2.2 +/- 0.5 MeV/fm(3). Neutron skin thicknesses of R-n-R-p = 0.23 +/- 0.03 fm and 0.24 +/- 0.03 fm for Sn-130 and Sn-132, respectively, have been determined. Preliminary results on Ni-68 from a similar experiment using an improved setup indicate an enhanced cross section at low energies, while the results for Ni-58 are in accordance with results from photoabsorption measurements.
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| 3. |
- Müller Kratz, Jadel, et al.
(författare)
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Anti-HSV-1 and anti-HIV-1 activity of gallic acid and pentyl gallate.
- 2008
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Ingår i: Memórias do Instituto Oswaldo Cruz. - 1678-8060. ; 103:5, s. 437-42
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Tidskriftsartikel (refereegranskat)abstract
- The synthetic n-alkyl esters of gallic acid (GA), also known as gallates, especially propyl, octyl and dodecyl gallates, are widely employed as antioxidants by food and pharmaceutical industries. The inhibitory effects of GA and 15 gallates on Herpes Simplex Virus type 1 (HSV-1) and Human Immunodeficiency Virus (HIV-1) replication were investigated here. After a preliminary screening of these compounds, GA and pentyl gallate (PG) seemed to be the most active compounds against HSV-1 replication and their mode of action was characterized through a set of assays, which attempted to localize the step of the viral multiplication cycle where impairment occurred. The detected anti-HSV-1 activity was mediated by the inhibition of virus attachment to and penetration into cells, and by virucidal properties. Furthermore, an anti-HIV-1 activity was also found, to different degrees. In summary, our results suggest that both compounds could be regarded as promising candidates for the development of topical anti-HSV-1 agents, and further studies concerning the anti-HIV-1 activity of this group of molecules are merited.
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| 4. |
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| 5. |
- Hayek, W, et al.
(författare)
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The Hamburg/ESO R-process enhanced star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312
- 2009
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 504:2, s. 511-524
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Tidskriftsartikel (refereegranskat)abstract
- We report on a detailed abundance analysis of two strongly r-process enhanced, very metal-poor stars newly discovered in the HERES project, CS 29491-069 ([Fe/H] = -2.51, [r/Fe] = +1.1) and HE 1219-0312 ([Fe/H] = -2.96, [r/Fe] = +1.5). The analysis is based on high-quality VLT/UVES spectra and MARCS model atmospheres. We detect lines of 15 heavy elements in the spectrum of CS 29491-069, and 18 in HE 1219-0312; in both cases including the Th II 4019 angstrom line. The heavy-element abundance patterns of these two stars are mostly well-matched to scaled solar residual abundances not formed by the s-process. We also compare the observed pattern with recent high-entropy wind (HEW) calculations, which assume core-collapse supernovae of massive stars as the astrophysical environment for the r-process, and find good agreement for most lanthanides. The abundance ratios of the lighter elements strontium, yttrium, and zirconium, which are presumably not formed by the main r-process, are reproduced well by the model. Radioactive dating for CS 29491-069 with the observed thorium and rare-earth element abundance pairs results in an average age of 9.5 Gyr, when based on solar r-process residuals, and 17.6 Gyr, when using HEW model predictions. Chronometry seems to fail in the case of HE 1219-0312, resulting in a negative age due to its high thorium abundance. HE 1219-0312 could therefore exhibit an overabundance of the heaviest elements, which is sometimes called an "actinide boost".
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