Domain wall description of superconductivity

In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted through the fact that the soliton following accelerating orbits is a Rindler observer experiencing a thermal bath.Comment: 9 pages, 5 figures, Latex. Version to appear in PL

Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications

Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo López for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETE—Operational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. Nachón is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin

Vortex avalanches in the non-centrosymmetric superconductor Li2Pt3B

We investigated the vortex dynamics in the non-centrosymmetric superconductor Li_2Pt_3B in the temperature range 0.1 K - 2.8 K. Two different logarithmic creep regimes in the decay of the remanent magnetization from the Bean critical state have been observed. In the first regime, the creep rate is extraordinarily small, indicating the existence of a new, very effective pinning mechanism. At a certain time a vortex avalanche occurs that increases the logarithmic creep rate by a factor of about 5 to 10 depending on the temperature. This may indicate that certain barriers against flux motion are present and they can be opened under increased pressure exerted by the vortices. A possible mechanism based on the barrier effect of twin boundaries is briefly discussed

On the Stability of Fundamental Couplings in the Galaxy

Astrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu=m_p/m_e$ within the Galaxy. We revisit and improve upon the analysis by Truppe {\it et al.} by allowing for the possibility of simultaneous variations of both couplings and also by combining them with the recent measurements by Levshakov {\it et al.} By considering representative unification scenarios we find no evidence for variations of $\alpha$ at the 0.4 ppm level, and of $\mu$ at the 0.6 ppm level; if one uses the Levshakov bound on $\mu$ as a prior, the$\alpha$ bound is improved to 0.1 ppm. We also highlight how these measurements can constrain (and discriminate among) several fundamental physics paradigms.Comment: 7 pages, 1 figur

On virialization with dark energy

We review the inclusion of dark energy into the formalism of spherical collapse, and the virialization of a two-component system, made of matter and dark energy. We compare two approaches in previous studies. The first assumes that only the matter component virializes, e.g. as in the case of a classic cosmological constant. The second approach allows the full system to virialize as a whole. We show that the two approaches give fundamentally different results for the final state of the system. This might be a signature discriminating between the classic cosmological constant which cannot virialize and a dynamical dark energy mimicking a cosmological constant. This signature is independent of the measured value of the equation of state. An additional issue which we address is energy non-conservation of the system, which originates from the homogeneity assumption for the dark energy. We propose a way to take this energy loss into account.Comment: 15 pages, 5 figures. Accepted for publication in JCA

Obtenção de cultivares de malva sem dormência nas sementes com boa produção e boa qualidade de fibra.

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Competição entre cultivares de juta local vs linhagens introduzidas da Índia.

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