530 research outputs found
Superconducting Properties of Carbonaceous Chemical Doped MgB2
The discovery of superconductivity in magnesium diboride (MgB2: 39 K, in January 2001) (Nagamatsu et al., 2001) has generated enormous interest and excitement in the superconductivity community and the world in general, but especially among researchers into superconductivity in non-oxide and boron related compounds
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Assessing the implementation of Sustainable Development Goals through switching cost
An increasing number of corporations are adapting their strategies to include projects aimed at achieving United Nations’ Sustainable Development Goals. Nonetheless, the implementation of these projects revives a fifty-year old question about the impact of sustainable activity on corporate financial performance and sustainability outcomes. This paper proposes the analysis of the Switching Costs of sustainable projects as a way to identify areas of improvement for corporate strategies, thus responding to the urgent need for models and assessment tools able to achieve financial and sustainability objectives as claimed by both practice and academia. A conceptual framework relating the Switching Costs of sustainable projects to sustainability and corporate financial performance has been developed and applied in this research to a case-study company, Walmart Mexico and Central America. This paper addresses the challenge of recognising, collecting and gauging the effect of the changes, particularly those of an intangible nature, generated by the sustainable projects
Coronal lines and the importance of deep core-valence correlation in Ag-like ions
We report on large-scale and critically evaluated {\em ab initio} MCDHF
calculations of the wavelength of the "coronal", M1 transition $4f\
^2\mathrm{F}_{5/2}^o-^2\mathrm{F}_{7/2}^oZ
\ge 62^{23+}^{27+}Z = 5094n=3$ shell in the theoretical model is emphasized. The
results show close to spectroscopic accuracy for these forbidden lines.Comment: 10 pages, 5 figures, 3 table
The effect of an external magnetic field on the determination of E1M1 two-photon decay rates in Be-like ions
In this work we report on ab initio theoretical results for the magnetic
field induced 2s2p ^3P_0 - 2s^2 ^1S_0 E1 transition for ions in the beryllium
isoelectronic sequence between Z=5 and 92. It has been proposed that the rate
of the E1M1 two-photon transition 2s2p ^3P_0 - 2s^2 ^1S_0 can be extracted from
the lifetime of the ^3P_0 state in Be-like ions with zero nuclear spin by
employing resonant recombination in a storage-ring. This experimental approach
involves a perturbing external magnetic field. The effect of this field needs
to be evaluated in order to properly extract the two-photon rate from the
measured decay curves. The magnetic field induced transition rates are
carefully evaluated and it is shown that, with a typical storage-ring field
strength, it is dominant or of the same order as the E1M1 rate for low- and
mid-Z ions. Results for several field strengths and ions are presented and we
also give a simple Z-dependent formula for the rate. We estimate the
uncertainties of our model to be within 5% for low- and mid-Z ions, and
slightly larger for more highly charged ions. Furthermore we evaluate the
importance of including both perturber states, ^3P_1 and ^1P_1, and it is shown
that excluding the influence of the ^1P_1 perturber overestimates the rate by
up to 26% for the mid-Z ions.Comment: 21 pages, 5 figure
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