Electrically charged pulsars

n the present work we investigate one possible variation on the usual electrically neutral pulsars: the inclusion of electric charge. We study the effect of electric charge in pulsars assuming that the charge distribution is proportional to the energy density. All calculations were performed for zero temperature and fixed entropy equations of state

Caloric curve for finite nuclei in relativistic models

In this work we calculate the caloric curve (excitation energy per particle as a function of temperature) for finite nuclei within the non--linear Walecka model for different proton fractions. It is shown that the caloric curve is sensitive to the proton fraction. Freeze-out volume effects in the caloric curve are also studied.Comment: 11 pages, 1 figure, 4 table

Low density expansion and isospin dependence of nuclear energy functional: comparison between relativistic and Skyrme models

In the present work we take the non relativistic limit of relativistic models and compare the obtained functionals with the usual Skyrme parametrization. Relativistic models with both constant couplings and with density dependent couplings are considered. While some models present very good results already at the lowest order in the density, models with non-linear terms only reproduce the energy functional if higher order terms are taken into account in the expansion.Comment: 16 pages,6 figures,5 table

Quark matter equation of state and stellar properties

In this paper we study strange matter by investigating the stability window within the QMDD model at zero temperature and check that it can explain the very massive pulsar recently detected. We compare our results with the ones obtained from the MIT bag model and see that the QMDD model can explain larger masses, due to the stiffening of the equation of state

Remarkable thermal stability of BF3-doped polyaniline

We show that the recently synthesized BF3-doped polyaniline (PANI) exhibits remarkable stability against thermal ageing. Unlike the protonated PANI, which shows rapid degradation of the conductivity on heating in air, BF3-doped PANI shows more than an order of magnitude improvement in conductivity. We employ x-ray photoelectron spectroscopy (XPS), fourier transform infra-red (FTIR) spectroscopy, and x-ray diffraction (XRD) to understand this unexpected phenomenon.Comment: 4 pages and 3 figures. To appear in Applied Physics Letters, Sept. 200