142 research outputs found

    On the isospin dependence of the mean spin-orbit field in nuclei

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    By the use of the latest experimental data on the spectra of 133^{133}Sb and 131^{131}Sn and on the analysis of properties of other odd nuclei adjacent to doubly magic closed shells the isospin dependence of a mean spin-orbit potential is defined. Such a dependence received the explanation in the framework of different theoretical approaches.Comment: 52 pages, Revtex, no figure

    Strategic Withholding through Production Failures

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    Anecdotal evidence indicates that electricity producers use production failures to disguise strategic reductions of capacity in order to influence prices, but systematic evidence is lacking. We use a quasi-experimental set up and data from the Swedish energy market to examine such behavior. In a market without strategic withholding, the decision of reporting a failure should be independent of the market price. We show that marginal producers in fact base their decision to report a failure in part on prices, which indicates that failures are a result of economic incentives as well as of technical problems

    Low momentum nucleon-nucleon potential and shell model effective interactions

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    A low momentum nucleon-nucleon (NN) potential V-low-k is derived from meson exhange potentials by integrating out the model dependent high momentum modes of V_NN. The smooth and approximately unique V-low-k is used as input for shell model calculations instead of the usual Brueckner G matrix. Such an approach eliminates the nuclear mass dependence of the input interaction one finds in the G matrix approach, allowing the same input interaction to be used in different nuclear regions. Shell model calculations of 18O, 134Te and 135I using the same input V-low-k have been performed. For cut-off momentum Lambda in the vicinity of 2 fm-1, our calculated low-lying spectra for these nuclei are in good agreement with experiments, and are weakly dependent on Lambda.Comment: 5 pages, 5 figure

    Quadrupole-deformed and octupole collective bands in 228^{228}Ra

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    Spins and parities for collective states in 228^{228}Ra have been determined from conversion electron measurements with a mini-orange β\beta-spectrometer. The fast-timing βγγ(t)\beta\gamma\gamma(t) method has been used to measure lifetimes of T1/2_{1/2}=550(20) ps and 181(3) ps for the 21+2^{+}_{1} and 41+4^{+}_{1} members of the K=0+^{+} band, and T1/2⩽_{1/2} \leqslant 7 ps and ⩽\leqslant 6 ps for the 11−1^{-}_{1} and 31−3^{-}_1 members of the K = 0−0^{-} band, respectively The quadrupole moments, Q0Q_{0} deduced from the B (E2; 21+→01+_{1}^{+} \rightarrow 0_{1}^{+}) and B (E2; 41+→21+_{1}^{+} \rightarrow 2_1^{+}) rates are in good agreement with the previously measured value and the systematics of the region. However, the B(E1) rates of ⩾\geqslant 4 × 10−4^{−4} e2^{2}fm2^{2}, which represent the first B(E1) measurements for this nucleus, are at least 25 times larger than the value previously suggested for 228^{228}Ra. The new results are consistent with the B(E1) rates recently measured for the neighbouring 227^{227}Ra and reveal octupole correlations in 228^{228}Ra

    When does the co-evolution of technology and science overturn into technoscience?

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    In this paper, the relations between science and technology, intervention and representation, the natural and the artificial are analysed on the background of the formation of modern science in the sixteenth century. Due to the fact that technique has been essential for modern science from its early beginning, modern science is characterised by a hybridisation of knowledge and intervention. The manipulation of nature in order to measure its properties has steadily increased until artificial things have been produced, such as laser beams, chemical compounds, elementary particles. Furthermore, the structural bracing of natural science, technological development, and industrial exploitation of nature go also back to the foundation of modern science. In order to strengthen the debate on technoscience against this background, the specific characteristics of technoscientific objects have to be clarified as have the specific characteristics of the social organisation of technoscience and its performance

    Population of a low-spin positive-parity band from high-spin intruder states in 177Au : The two-state mixing effect

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    The extremely neutron-deficient isotopes 177,179Au were studied by means of in-beam Îł-ray spectroscopy. Specific tagging techniques, Îą-decay tagging in 177Au and isomer tagging in 179Au, were used for these studies. Feeding of positive-parity, nearly spherical states, which are associated with 2d3/2 and 3s1/2 proton-hole configurations, from the 1i13/2 proton-intruder configuration was observed in 177Au. Such a decay path has no precedent in odd-Au isotopes and it is explained by the effect of mixing of wave functions of the initial state

    Scoping review of indicators and methods of measurement used to evaluate the impact of dog population management interventions

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    Background: Dogs are ubiquitous in human society and attempts to manage their populations are common to most countries. Managing dog populations is achieved through a range of interventions to suit the dog population dynamics and dog ownership characteristics of the location, with a number of potential impacts or goals in mind. Impact assessment provides the opportunity for interventions to identify areas of inefficiencies for improvement and build evidence of positive change. Methods: This scoping review collates 26 studies that have assessed the impacts of dog population management interventions. Results: It reports the use of 29 indicators of change under 8 categories of impact and describes variation in the methods used to measure these indicators. Conclusion: The relatively few published examples of impact assessment in dog population management suggest this field is in its infancy; however this review highlights those notable exceptions. By describing those indicators and methods of measurement that have been reported thus far, and apparent barriers to efficient assessment, this review aims to support and direct future impact assessment
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