Erosion resistant coatings

Apparatus for measuring the resistance of materials to erosion is examined and a scheme for standardization of the test parameters is described. Current materials being used for protecting aircraft parts from erosion are surveyed, their chief characteristics being given. The superior properties of urethane coatings are pointed out. The complete cycle for painting areas subject to erosion is described

Instanton theory for bosons in disordered speckle potential

We study the tail of the spectrum for non-interacting bosons in a blue-detuned random speckle potential. Using an instanton approach we derive the asymptotic behavior of the density of states in d dimensions. The leading corrections resulting from fluctuations around the saddle point solution are obtained by means of the Gel'fand-Yaglom method generalized to functional determinants with zero modes. We find a good agreement with the results of numerical simulations in one dimension. The effect of weak repulsive interactions in the Lifshitz tail is also discussed.Comment: 12 pages, 3 figures, revtex

Vector meson production in pp collisions at s=7 TeV\sqrt{s}=7\rm{~TeV}, measured with the ALICE detector

Vector mesons are key probes of the hot and dense state of strongly interacting matter produced in heavy ion collisions. Their dileptonic decay channel is particularly suitable for these studies, since dileptons have negligible final state interactions in hadronic matter. A preliminary measurement of the $\phi$ and $\omega$ differential cross sections was performed by the ALICE experiment in pp collisions at $\sqrt{s}=7$ TeV, through their decay in muon pairs. The $p_{\rm T}$ and rapidity regions covered in this analysis are $p_{\rm T}>1$ GeV$/c$ and $2.5 < y < 4$.Comment: 4 pages, 4, figures, proceedings of the Quark Matter 2011 conferenc

Editorial: new challenges In theory and practice of corporate governance

The aim of international conference “New Challenges in Corporate Governance: Theory And Practice” is to move the field closer to a global theory by advancing our understanding of corporate governance, which combines insights from the literature on firm governance bundles with insights from the national governance systems literature, investigating new perspectives and challenges for corporate governance and outlining possible scenarios of its development

Why does the Jeans Swindle work?

When measuring the mass profile of any given cosmological structure through internal kinematics, the distant background density is always ignored. This trick is often refereed to as the "Jeans Swindle". Without this trick a divergent term from the background density renders the mass profile undefined, however, this trick has no formal justification. We show that when one includes the expansion of the Universe in the Jeans equation, a term appears which exactly cancels the divergent term from the background. We thereby establish a formal justification for using the Jeans Swindle.Comment: 5 pages, 2 figures, Accepted for publication in MNRAS Letter

Wave function correlations and the AC conductivity of disordered wires beyond the Mott-Berezinskii law

In one-dimensional disordered wires electronic states are localized at any energy. Correlations of the states at close positive energies and the AC conductivity $\sigma(\omega)$ in the limit of small frequency are described by the Mott-Berezinskii theory. We revisit the instanton approach to the statistics of wave functions and AC transport valid in the tails of the spectrum (large negative energies). Applying our recent results on functional determinants, we calculate exactly the integral over gaussian fluctuations around the exact two-instanton saddle point. We derive correlators of wave functions at different energies beyond the leading order in the energy difference. This allows us to calculate corrections to the Mott-Berezinskii law (the leading small frequency asymptotic behavior of $\sigma(\omega)$) which approximate the exact result in a broad range of $\omega$. We compare our results with the ones obtained for positive energies.Comment: 7 pages, 3 figure

Lifetime statistics of quantum chaos studied by a multiscale analysis

In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a Silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines graph theory, energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.Comment: 4 pages, 6 figure