Dielectric relaxation and ferromagnetic resonance in magnetoelectric (Polyvinylidene-fluoride)/ferrite composites

In this work the dielectric properties and ferromagnetic resonance of Polyvinylidene- uoride embedded with 10 wt. % of NiFe2O4 or Ni0.5Zn0.5Fe2O4 nanoparticles are presented. The mechanisms of the dielectric relaxation in these two composites do not differ from each other. For more precise characterization of the dielectric relaxation, a two dimensional distribution of relaxation times was calculated from the temperature dependencies of the complex dielectric permittivity. The results obtained from the 2D distribution and the mean relaxation time are found to be consistent. The dynamics of the dielectric permittivity is described by the Arrhenius law. The energy and attempt time of the dielectric relaxators lie in a narrow energy and time region thus proving that the single type chains of polymer are responsible for a dispersion. The magnetic properties of the composites were investigated using the fer- romagnetic resonance. A single resonance line was observed for both samples. From the temperature dependence (100 K - 310 K) of the resonance eld and linewidth, the origin of the observed line was attributed to the NiFe2O4 and Ni0.5Zn0.5Fe2O4 superparamagnetic nanoparticles. By measuring lms at dif- ferent orientations with respect to the external magnetic eld, the angular dependence of the resonance was observed, indicating the magnetic dipolar in-plane interactions.

Thrombophilia screening: An artificial neural network approach

Thrombotic disorders have severe consequences for the patients and for the society in general, being one of the main causes of death. These facts reveal that it is extremely important to be preventive; being aware of how probable is to have that kind of syndrome. Indeed, this work will focus on the development of a decision support system that will cater for an individual risk evaluation with respect to the surge of thrombotic complaints. The Knowledge Representation and Reasoning procedures used will be based on an extension to the Logic Programming language, allowing the handling of incomplete and/or default data. The computational framework in place will be centered on Artificial Neural Networks.

Searches for heavy long-lived charged particles with the ATLAS detector in proton--proton collisions at s√ = 8 TeV

Searches for heavy long-lived charged particles are performed using a data sample of 19.8 fb−1 from proton--proton collisions at a centre-of-mass energy of s√ = 8 TeV collected by the ATLAS detector at the Large Hadron Collider. No excess is observed above the estimated background and limits are placed on the mass of long-lived particles in various supersymmetric models. Long-lived tau sleptons in models with gauge-mediated symmetry breaking are excluded up to masses between 440 and 385 GeV for tan(beta) between 10 and 50, with a 290 GeV limit in the case where only direct tau slepton production is considered. In the context of simplified LeptoSUSY models, where sleptons are stable and have a mass of 300 GeV, squark and gluino masses are excluded up to a mass of 1500 and 1360 GeV, respectively. Directly produced charginos, in simplified models where they are nearly degenerate to the lightest neutralino, are excluded up to a mass of 620 GeV. R-hadrons, composites containing a gluino, bottom squark or top squark, are excluded up to a mass of 1270, 845 and 900 GeV, respectively, using the full detector; and up to a mass of 1260, 835 and 870 GeV using an approach disregarding information from the muon spectrometer.