146 research outputs found

    Ground deposition of long-lived gamma emitters in Poland from the Chernobyl accident

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    Activity composition was measured for soil contaminated with the fallout from the Chernobyl accident. The soil samples were collected at various areas of Poland. A map showing the 137^{137}Cs deposit distribution was drawn for the most contaminated southern part of Poland

    Okazja jako wyznacznik przedsiębiorstwa zwinnego – studium przypadku

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    The environment of the organization creates opportunities and threats for the enterprise. Enterprises identify the possibility of benefiting either intentionally or unintentionally. One way to benefit in the business environment is to seize the opportunity. An opportunity is understood as a situation conducive to the subject of action. The domain of agile enterprises is the ability to capture and use of the opportunity. The article presents the theoretical and practical issues. The theoretical part discusses the issue of agile enterprise and opportunity. The empirical part presents the results of research, which showed the agile behavior of the organization that led to the use of opportunities.Otoczenie organizacji kreuje szanse i zagrożenia dla przedsiębiorstwa. Przedsiębiorstwa identyfikują możliwość odniesienia korzyści w sposób celowy lub niezamierzony. Jednym ze sposobów odniesienia korzyści w otoczeniu przedsiębiorstwa jest wykorzystanie okazji. Okazja jest rozumiana jako sytuacja sprzyjająca podmiotowi działania. Umiejętność jej uchwycenia i wykorzystania jest domeną przedsiębiorstw zwinnych. W opracowaniu przedstawiono ujęcie teoretyczne i praktyczne zagadnienia. W części teoretycznej omówiono zagadnienia przedsiębiorstwa zwinnego i okazji. W części empirycznej przedstawiono wyniki badań, w ramach których zostały ukazane zwinne zachowania organizacji, które doprowadziły do wykorzystania okazj

    Zygmunt Florenty Wróblewski (1845-1888)

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    Nature of yrast excitations near N=40: Level structure of Ni-67

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    Excited states in Ni-67 were populated in deep-inelastic reactions of a Ni-64 beam at 430 MeV on a thick U-238 target. A level scheme built on the previously known 13 micro-s isomer has been delineated up to an excitation energy of ~5.3 MeV and a tentative spin and parity of (21/2-). Shell model calculations have been carried out using two effective interactions in the f5/2pg9/2 model space with a Ni-56 core. Satisfactory agreement between experiment and theory is achieved for the measured transition energies and branching ratios. The calculations indicate that the yrast states are associated with rather complex configurations, herewith demonstrating the relative weakness of the N=40 subshell gap and the importance of multi particle-hole excitations involving the g9/2 neutron orbital.Comment: Accepted by Physical Review

    Beta decay of 71,73Co; probing single particle states approaching doubly magic 78Ni

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    Low-energy excited states in 71,73Ni populated via the {\beta} decay of 71,73Co were investigated in an experiment performed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). Detailed analysis led to the construction of level schemes of 71,73Ni, which are interpreted using systematics and analyzed using shell model calculations. The 5/2- states attributed to the the f5/2 orbital and positive parity 5/2+ and 7/2+ states from the g9/2 orbital have been identified in both 71,73Ni. In 71Ni the location of a 1/2- {\beta}-decaying isomer is proposed and limits are suggested as to the location of the isomer in 73Ni. The location of positive parity cluster states are also identified in 71,73Ni. Beta-delayed neutron branching ratios obtained from this data are given for both 71,73Co.Comment: Accepted for publication in PR

    Influence of entrance-channel magicity and isospin on quasi-fission

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    The role of spherical quantum shells in the competition between fusion and quasi-fission is studied for reactions forming heavy elements. Measurements of fission fragment mass distributions for different reactions leading to similar compound nuclei have been made near the fusion barrier. In general, more quasi-fission is observed for reactions with non-magic nuclei. However, the 40^{40}Ca+208^{208}Pb reaction is an exception, showing strong evidence for quasi-fission, though both nuclei are doubly magic. Time-dependent Hartree-Fock calculations predict fast equilibration of N/ZN/Z in the two fragments early in the collision. This transfer of nucleons breaks the shell effect, causing this reaction to behave more like a non-magic one in the competition between fusion and quasi-fission. Future measurements of fission in reactions with exotic beams should be able to test this idea with larger N/ZN/Z asymmetries.Comment: accepted for publication in Physics Letters

    New approach to the conceptual design of STUMM: A module dedicated to the monitoring of neutron and gamma radiation fields generated in IFMIF-DONES

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    International Fusion Materials Irradiation Facility — DEMOsingle bondOriented Neutron Source (IFMIF-DONES) is a planned powerful neutron source, which will generate an intense flux of neutrons (up to ∼1015n/s/cm2) with a fusion-relevant energy spectrum. It will be an accelerator source based on deuteron beam - lithium target reactions. The engineering design of IFMIF-DONES is elaborated in the frame of the Early Neutron Source work package of the EUROfusion consortium. The facility will be dedicated to the irradiation of suitable structural materials planned for the construction of future fusion reactors such as DEMO (Demonstration Fusion Power Plant). Start-up Monitoring Module (STUMM) is designed to monitor radiation and thermal conditions during the commissioning phase of IFMIF-DONES, characterize the produced neutron flux and validate neutronic modeling of the facility. The conceptual design of STUMM is prepared by a team of physicists and engineers from the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN) and the National Centre for Nuclear Research (NCBJ), Poland. This paper presents the concept of STUMM, the proposed design of the module, and selected measuring systems

    Low temperature spin fluctuations in geometrically frustrated Yb3Ga5O12

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    In the garnet structure compound Yb3Ga5O12, the Yb3+ ions (ground state effective spin S' = 1/2) are situated on two interpenetrating corner sharing triangular sublattices such that frustrated magnetic interactions are possible. Previous specific heat measurements evidenced the development of short range magnetic correlations below 0.5K and a lambda-transition at 54mK (Filippi et al. J. Phys. C: Solid State Physics 13 (1980) 1277). From 170-Yb M"ossbauer spectroscopy measurements down to 36mK, we find there is no static magnetic order at temperatures below that of the lambda-transition. Below 0.3K, the fluctuation frequency of the short range correlated Yb3+ moments progressively slows down and as the temperature tends to 0, the frequency tends to a quasi-saturated value of 3 x 10^9 s^-1. We also examined the Yb3+ paramagnetic relaxation rates up to 300K using 172-Yb perturbed angular correlation measurements: they evidence phonon driven processes.Comment: 6 pages, 5 figure

    Penning-Trap Mass Measurements of the Neutron-Rich K and Ca Isotopes: Resurgence of the N = 28 Shell Strength

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    We present Penning-trap mass measurements of neutron-rich 44,47-50K and 49,50Ca isotopes carried out at the TITAN facility at TRIUMF-ISAC. The 44K mass measurement was performed with a charge-bred 4+ ion utilizing the TITAN EBIT, and agrees with the literature. The mass excesses obtained for 47K and 49,50Ca are more precise and agree with the values published in the 2003 Atomic Mass Evaluation (AME'03). The 48,49,50K mass excesses are more precise than the AME'03 values by more than one order of magnitude. For 48,49K, we find deviations by 7 sigma and 10 sigma, respectively. The new 49K mass excess lowers significantly the two-neutron separation energy at the neutron number N=30 compared with the separation energy calculated from the AME'03 mass-excess values, and thus, increases the N=28 neutron-shell gap energy at Z=19 by approximately 1 MeV.Comment: 6 pages, 5 figures, accepted for PR

    Project Status of the Polish Synchrotron Radiation Facility Solaris

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    Abstract in Undetermined The Polish synchrotron radiation facility Solaris is being built at the Jagiellonian University in Krakow. The project is based on an identical copy of the 1.5 GeV storage ring being concurrently built for the MAX IV project in Lund, Sweden. A general description of the facility is given together with a status of activities. Unique features associated with Solaris are outlined, such as infrastructure, the injector and operational characteristics
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