Aksahin, E. | Ustoglu Unal, V. | Tomak, M.

Article | 2014 | European Physical Journal B87 ( 11 )

An exciton in a spherical quantum dot is studied analytically within the effective mass approximation. A parabolic confinement under an electric field is considered. The linear and nonlinear optical absorption coefficients are calculated within the density matrix formalism. No assumptions are made about the strength of the confinement. It is shown how the competing mechanisms of the Coulomb interaction, the confinement and the applied static electric field affect the optical absorption. © 2014, EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

Topal, U. | Coker, E.G. | Alıkma, F. | Kolemen, U. | Uzun, O.

Article | 2014 | Journal of Superconductivity and Novel Magnetism27 ( 1 ) , pp.133 - 141

The second harmonic signal, which is generated by co-application of AC and DC fields to polycrystalline type-II superconductors, were analyzed in terms of the weak links and the critical current density. With this aim the YBa 2 Cu 3-x Zn x O 7-y (x=0, 0.01, 0.02, 0.03, 0.05, and 0.1) samples were synthesized in order to adjust intergranular couplings and thus the strength of weak links. The mechanical and magnetic measurements are in good agreement on that Zn doping reduces strength of the links between grains; however, contrary to the common expectations, it has no direct contribution to the 2nd harmonic signal strength. © 2013 Spr . . .inger Science+Business Media New York Daha fazlası Daha az

Pedamallu, C.S. | Ozdamar, L. | Weber, G.-W.

Conference Object | 2014 | Springer Proceedings in Mathematics and Statistics73 , pp.521 - 538

International Conference on Modeling, Optimization and Dynamics, ICMOD 2010 and 5th Bioeconomy Conference 2012 -- 5 July 2010 through 7 July 2010 -- -- 117169

Gülce Çoker, E. | Kolemen, U. | Topal, U.

Article | 2014 | Journal of Superconductivity and Novel Magnetism28 ( 2 ) , pp.513 - 518

The effect of the intergranular couplings on the second harmonic of the fundamental signal, which is generated by co-application of DC and AC fields to a magnetic material having nonlinear magnetization, was investigated on B 2O3 doped YBaCuO superconductors. Physical and mechanical properties of B 2O3 doped YBaCuO superconductors were also analyzed to support electrical measurements. © 2014, Springer Science+Business Media New York.

Pedamallu, C.S. | Ozdamar, L.

Conference Object | 2014 | Springer Proceedings in Mathematics and Statistics73 , pp.511 - 519

International Conference on Modeling, Optimization and Dynamics, ICMOD 2010 and 5th Bioeconomy Conference 2012 -- 5 July 2010 through 7 July 2010 -- -- 117169