19 research outputs found

    Optical properties of BaFe2x_{2-x}Cox_xAs2_2

    Get PDF
    We present detailed temperature dependent optical data on BaFe2x_{2-x}Cox_{x}As2_{2} (BCFA), with x = 0.14, between 4 meV and 6.5 eV. We analyze our spectra to determine the main optical parameters and show that in this material the interband conductivity already starts around 10 meV. We determine the superfluid density to be 2.2 10^{7}cm2,whichplacesoptimallydopedBFCAclosetotheUemuraline.Ourexperimentaldatashowsclearsignsofasuperconductinggapwith2 cm^{-2}, which places optimally doped BFCA close to the Uemura line. Our experimental data shows clear signs of a superconducting gap with 2\Delta_{1}=6.2 = 6.2 \pm0.8meV.Inadditionweshowthattheopticalspectraareconsistentwiththepresenceofanadditionalbandofstronglyscatteredcarrierswithalargergap,2 0.8 meV. In addition we show that the optical spectra are consistent with the presence of an additional band of strongly scattered carriers with a larger gap, 2\Delta_{2}=14 = 14 \pm$ 2 meV.Comment: 5 pages, 4 figure

    Post-traumatic fulminant paradoxical fat embolism syndrome in conjunction with asymptomatic atrial septal defect: a case report and review of the literature

    Get PDF
    Fat embolism syndrome may occur as a fulminant complication following femoral fracture repair in the presence of a concomitant atrial septal defect with right-to-left shunt. Thus, in patients with cardiac right-to-left shunts, femurs should not be nailed intramedullary, not even in cases of isolated injuries

    Primal-dual stability in continuous linear optimization

    Get PDF
    Any linear (ordinary or semi-infinite) optimization problem, and also its dual problem, can be classified as either inconsistent or bounded or unbounded, giving rise to nine duality states, three of them being precluded by the weak duality theorem. The remaining six duality states are possible in linear semi-infinite programming whereas two of them are precluded in linear programming as a consequence of the existence theorem and the non-homogeneous Farkas Lemma. This paper characterizes the linear programs and the continuous linear semi-infinite programs whose duality state is preserved by sufficiently small perturbations of all the data. Moreover, it shows that almost all linear programs satisfy this stability property.This research was supported by DGES and FEDER, Grant MTM2005-08572-C03-01 and partially supported by CONACyT of MX.Grant 44003
    corecore