39,544 research outputs found
Crystal structure prediction using the Minima Hopping method
A structure prediction method is presented based on the Minima Hopping
method. Optimized moves on the configurational enthalpy surface are performed
to escape local minima using variable cell shape molecular dynamics by aligning
the initial atomic and cell velocities to low curvature directions of the
current minimum. The method is applied to both silicon crystals and binary
Lennard-Jones mixtures and the results are compared to previous investigations.
It is shown that a high success rate is achieved and a reliable prediction of
unknown ground state structures is possible.Comment: 9 pages, 6 figures, novel approach in structure prediction, submitted
to the Journal of Chemical Physic
Distributional Effects of Fiscal Consolidation.
This paper examines the distributional consequences of public debt reduction achieved through spending cuts. Under the assumption that public goods and transfers are relatively more valuable to the poor, our calculations indicate that the elderly poor stand to lose from such policies. Debt reduction produces short-term deficits and long-term surpluses, and when future surpluses are recycled into higher provision of public goods and transfers, future generations of poor could gain. If future surpluses are recycled through lower labour taxes, working households in the future would be positively affected. We conclude that debt reduction could have positive or negative impacts on vertical equity, yet inter- rather than intra-generational equity is likely to pose the greatest obstacle to fiscal consolidation. Based on majority voting by self-interested households, debt reduction would never occur. Yet, in a formal social welfare analysis, some debt reduction programmes may be deemed beneficial with social discount factors as high as two percent. When we then consider alternative time profiles for debt reduction, we conclude that slower is better.
Carbon incorporation in ZnSe grown by metalorganic chemical vapor deposition
Carbon incorporation in ZnSe films grown by metalorganic chemical vapor deposition is reported. Secondary‐ion mass spectrometry measurements in ZnSe films grown from methylallylselenide and dimethylzinc show an enhanced carbon accumulation at the interface between ZnSe and GaAs. The carbon incorporation in the bulk ZnSe increases with the VI/II ratio and for a value of VI/II=3–4, the amount of incorporated carbon abruptly jumps to concentrations of 10^(21) cm^(−3), whereupon the films become polycrystalline. A new shallow peak I^C at 2.7920 eV dominates the near‐band‐edge low‐temperature photoluminescence spectra of all carbon‐contaminated ZnSe films. The intensity and linewidth of I^C increase with the VI/II ratio in a similar manner to the carbon concentration. This peak is proposed to be due to the radiative decay of excitons bound to a complex defect, which is associated with the presence of carbon in the films
Reconsidering "the love of art" : evaluating the potential of art museum outreach
Art museums have long been identified as bastions of social and cultural exclusion. This conclusion was best evidenced by the large-scale 1967 French study by Bourdieu and Darbel demonstrating the exclusionary nature of “The Love of Art.” However, in recent years there have been increasing efforts to reach out to a broader range of visitors beyond conventional
audiences. The present study investigates the impacts of an outreach program at a UK art museum, which sought to engage socially excluded young mothers. This study employs ethnographic research methods on a longitudinal basis to develop qualitative insights about the program seeking to mitigate cultural exclusion. While the study’s findings uphold many longstanding critiques of art museums’ conventional approaches, the study also indicates that carefully designed outreach activities can overcome such limitations and enhance cultural
engagement. Thus, art museums’ limited appeal is tied to problematic public engagement practices that can be changed
‘Original Practices’, Lost Plays, and Historical Imagination: Staging ‘The Tragedy of Merry’
This is the author accepted manuscript. The final version is available from Johns Hopkins University Press via the DOI in this record.No abstrac
Traceability in Food Systems: An Economic Analysis of LGMA and the 2006 Spinach Outbreak
This case study presents an in-depth review of network structures and costs associated with the implementation of traceability systems in California leafy green production, distribution, and retailing. The 2006 spinach outbreak is used to assess the economic impact of trace back/forward response time of the LGMA system, an example of a tightly coupled, linear supply network. Results suggest that the benefits of traceability systems may far outweigh the costs and that costs vary significantly by technology used and by grower size. Implications are derived for cost-effectiveness of rapid response, targeted trace back/forward systems in other types of supply networks.traceability, produce, supply networks, cost-effectiveness, Food Consumption/Nutrition/Food Safety, Production Economics, Q18, I18, L51,
Spherical near-field scanning at the Technical University of Denmark
The early work (1969-79) on spherical near-field antenna measurements at the Technical University of Denmark (TUD) is outlined. A spherical near-field transmission formula is described and the first probe-corrected spherical near-field measurements are discussed. The TUD-ESA (European Space Agency) joint effort on spherical near-field testing is also described
Study of the one-dimensional off-lattice hot-monomer reaction model
Hot monomers are particles having a transient mobility (a ballistic flight)
prior to being definitely absorbed on a surface. After arriving at a surface,
the excess energy coming from the kinetic energy in the gas phase is dissipated
through degrees of freedom parallel to the surface plane. In this paper we
study the hot monomer-monomer adsorption-reaction process on a continuum
(off-lattice) one-dimensional space by means of Monte Carlo simulations. The
system exhibits second-order irreversible phase transition between a reactive
and saturated (absorbing) phases which belong to the directed percolation (DP)
universality class. This result is interpreted by means of a coarse-grained
Langevin description which allows as to extend the DP conjecture to transitions
occurring in continuous media.Comment: 13 pages, 5 figures, final version to appear in J. Phys.
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