Radiation Effects on the Flow near the Stagnation Point of a Stretching Sheet

The present paper is concerned with the study of the radiation effects (Rosseland model) on the flow of an incompressible viscous fluid over a flat sheet near the stagnation point. The system of ordinary differential equations is solved numerically using the Runge-Kutta method coupled with a shooting technique. The results show that a boundary layer is formed and its thickness increases with the radiation, velocity and temperature parameters and decreases when the Prandtl number is increased

New rr-Matrices for Lie Bialgebra Structures over Polynomials

For a finite dimensional simple complex Lie algebra $\mathfrak{g}$, Lie bialgebra structures on $\mathfrak{g}[[u]]$ and $\mathfrak{g}[u]$ were classified by Montaner, Stolin and Zelmanov. In our paper, we provide an explicit algorithm to produce $r$-matrices which correspond to Lie bialgebra structures over polynomials

MHD Squeezing Flow Between Two Parallel Discs

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Free Convection about a Vertical Wavy Surface with Prescribed Surface Heat Flux in a Micropolar Fluid

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Electronic, optical and thermal properties of the hexagonal and fcc Ge2Sb2Te5 chalcogenide from first-principle calculations

We present a comprehensive computational study on the properties of face-centered cubic and hexagonal chalcogenide Ge2Sb2Te5. We calculate the electronic structure using density functional theory (DFT); the obtained density of states (DOS) compares favorably with experiments, also looking suitable for transport analysis. Optical constants including refraction index and absorption coefficient capture major experimental features, aside from an energy shift owed to an underestimate of the band gap that is typical of DFT calculations. We also compute the phonon DOS for the hexagonal phase, obtaining a speed of sound and thermal conductivity in good agreement with the experimental lattice contribution. The calculated heat capacity reaches ~ 1.4 x 106 J/(m3 K) at high temperature, in agreement with experimental data, and provides insight into the low-temperature range (< 150 K), where data are unavailable.Comment: 19 pages, 8 figure

Similarity Solutions for Boundary Layer Flows on a Moving Surface in Non-Newtonian Power-Law Fluids

A similarity analysis of the boundary layer flow caused by the motion of a semi-infinite flat sulface in a non-Newtonian power-law fluid at rest is made in this paper. These similar solutions fall into two categories: similarity solutions corresponding to steady boundary layers over moving surfaces and similarity solutions corresponding to unsteady boundary layers past moving flat surfaces, respectively. Except in the special case n = 1/2 (pseudoplastic) and n = 1 (Newtonian) fluids, solutions of the first category problems must be obtainednumerically. However, for the second category analytical solutions are possible for a large class of pseudoplasticfluids (n &lt; 1), including the case of a Newtonianfluid (n = 1)

Quantum phase-slips in Josephson junction rings

We study quantum phase-slip (QPS) processes in a superconducting ring containing N Josephson junctions and threaded by an external static magnetic flux. In a such system, a QPS consists of a quantum tunneling event connecting two distinct classical states of the phases with different persistent currents [K. A. Matveev et al., Phys. Rev. Lett. 89, 096802 (2002)]. When the Josephson coupling energy EJ of the junctions is larger than the charging energy EC = e2/2C where C is the junction capacitance, the quantum amplitude for the QPS process is exponentially small in the ratio EJ/EC. At given magnetic flux each QPS can be described as the tunneling of the phase difference of a single junction of almost 2pi, accompanied by a small harmonic displacement of the phase difference of the other N-1 junctions. As a consequence the total QPS amplitude nu is a global property of the ring. Here we study the dependence of nu on the ring size N taking into account the effect of a finite capacitance C0 to ground which leads to the appearance of low-frequency dispersive modes. Josephson and charging effects compete and lead to a nonmonotonic dependence of the ring critical current on N. For N=infty, the system converges either towards a superconducting or an insulating state, depending on the ratio between the charging energy E0 = e2/2C0 and the Josephson coupling energy EJ.Comment: (19 pages, 12 figures) The final version deviated from the original version. One of the author was removed from the lis

Reply to Comment of Gazdzicki and Heinz on Strangeness Enhancement in p+Ap+A and S+AS+A

The Comment of Gazdzicki and Heinz is flawed because their assumed baryon stopping power in $pA$ is inconsistent with data and because they ignored half the analysis based on the VENUS model. The Comment continues the misleading presentation of strangeness enhancement by focusing on ratios of integrated yields. Those ratios discard essential experimental information on the rapidity dependence of produced $\Lambda$ and obscure discrepancies between different data sets. Our conclusion remains that the NA35 minimum bias data on $p+S\rightarrow\Lambda +X$ indicate an anomalous enhancement of central rapidity strangeness in few nucleon reactions that points to non-equilibrium dynamics as responsible for strangeness enhancement in nuclear reactions.Comment: revtex file, 6 pages, submitted to Phys. Rev.