Approximate Solution of the Effective Mass Klein-Gordon Equation for the Hulthen Potential with Any Angular Momentum

The radial part of the effective mass Klein-Gordon equation for the Hulthen potential is solved by making an approximation to the centrifugal potential. The Nikiforov-Uvarov method is used in the calculations. Energy spectra and the corresponding eigenfunctions are computed. Results are also given for the case of constant mass.     

Some convexity properties of Dirichlet series with positive terms

Some basic results for Dirichlet series ψ with positive terms via log‐convexity properties are pointed out. Applications for Zeta, Lambda and Eta functions are considered. The concavity of the function 1/ψ is explored and, as a main result, it is proved that the function 1/ζ is concave on (ζ^–1(e), ∞). As a consequence of this fundamental result it is noted that Zeta at the odd positive integers is bounded above by the harmonic mean of its immediate even Zeta values which are known explicitly (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis of polystyrene/polybutylacrylate/layered silicate nanocomposites in aqueous medium

Synthesis of nanocomposites based on polystyrene/polybutylacrylate with layered silicates using emulsion polymerization procedure in aqueous medium allowed obtaining stable nanolatexes with sodium dodecyl sulfate as surfactant. Monomer and layered silicate nature influences the average diameter of the particles and the zeta potential appeared on the particle-disperse medium interface, as it was shown by dynamic light scattering analyses. In order to evidence the layered silicate structure, two structural evaluation methods were used. A new approach was used based on Fourier transform infrared analyses as a method to asses the clay delamination. The method was followed in conjunction with X-ray diffraction patterns and showed the pronounced delamination of the clay in the polymer matrix. The thermal stability was investigated by thermogravimetric analyses and the morphologies in solid state observed by environmental scanning electron microscope measurements.     

PT-Symmetric Solutions of Schrödinger Equation with Position-Dependent Mass via Point Canonical Transformation

PT-symmetric solutions of Schrödinger equation are obtained for the Scarf and generalized harmonic oscillator potentials with the position-dependent mass. A general point canonical transformation is applied by using a free parameter. Three different forms of mass distributions are used. A set of the energy eigenvalues of the bound states and corresponding wave functions for target potentials are obtained as a function of the free parameter.     

Trapezoidal type inequalities for n-time differentiable functions

In this paper we consider the flow shop scheduling problems with the effects of learning and deterioration. In this model the processing times of a job is defined as a function of its starting time and position in a sequence. The scheduling objective functions are makespan and total completion time. We prove that even with the introduction of learning effect and deteriorating jobs to job processing times, some special flow shop scheduling problems remain polynomially solvable.     

Systems of conservation laws with rotation and Galilean symmetry

We show that the structure of multidimensional systems of conservation laws, equipped with a single, convex entropy, and with both rotation and Galilean symmetries, is perhaps surprisingly limited. The following are established.The simplest examples of such systems, with only one vector field, are at most simple extensions of the familiar Euler systems.In such models of magnetohydrodynamic flow, including a solenoidal, Galilean invariant magnetic field, the property of finite signal propagation speeds is often lost.The only such system describing adiabatic multi-fluid flow, with the mass of each species conserved separately, corresponds to independent flow of each species. Whatever interaction between the different species occurs in an energy equation or through some other dependent variable, and not simply through expressions for the pressures in terms of the species? densities. A similar conclusion holds for incompressible flow.     

EPR investigation and spectral simulations of iron-catecholate complexes and iron-peptide models of marine adhesive cross-links

Electron paramagnetic resonance (EPR) spectra are presented for iron complexes of catecholate, tironate, and a 3,4-dihydroxyphenylalanine (DOPA)-containing peptide of sequence Ac-Ala-DOPA-Thr-Pro-CONH2 ("AdopaTP"). This peptide was prepared to model potential metal-protein cross-links in the adhesive used by marine mussels, Mytilus edulis, for affixing themselves to surfaces. Spectra are shown for iron bound to each ligand in mono, bis, and tris coordination environments. For example, the catecholate complexes {Fe(cat)}, {Fe(cat)2}, and [Fe(cat)3]3- are provided. Detailed simulations are presented to describe the origin of spectra for the iron-catecholate and iron-peptide species, which show that the spectral features can be accounted for only with the inclusion of D- and E-strain. The spectroscopy of each compound is shown under both anaerobic and aerobic conditions. When exposed to air, the high-spin Fe3+ signal of [Fe(AdopaTP)3]3- decreases and an organic radical is formed. No other sample exhibited an appreciable radical signal. These data are discussed in light of the biomaterial synthesis carried out by marine mussels.