Properties improvement of poly(o-methoxyaniline) based supercapacitors : experimental and theoretical behaviour study of self-doping effect

The support of this research by FAPESP (2011/10897-2, 2013/07296-2), CsF-PVE (99999.007708/2015-07), CAPES and CNPq is gratefully acknowledged. We also thank the University of Aberdeen for providing computational time on MaxwellPeer reviewedPostprin

Coupled-mode theory for periodic side-coupled microcavity and photonic crystal structures

We use a phenomenological Hamiltonian approach to derive a set of coupled mode equations that describe light propagation in waveguides that are periodically side-coupled to microcavities. The structure exhibits both Bragg gap and (polariton like) resonator gap in the dispersion relation. The origin and physical significance of the two types of gaps are discussed. The coupled-mode equations derived from the effective field formalism are valid deep within the Bragg gaps and resonator gaps.Comment: 13 pages, 6 figure

Dormência de pós-colheita em sementes de arroz de sequeiro e irrigado.

Foram conduzidos dois experimentos no período de novembro de 1994 a agosto de 1995, no Laboratório de Fisiologia Vegetal do Centro de Pesquisa Agropecuária do Meio-Norte (CPAMN), da Embrapa, em Parnaíba, Piaui, com sementes de duas cultivares de arroz de sequeiro (Caiapó e Uruçuí) e uma de arroz irrigado (Diamante). O estudo teve como objetivo avaliar a possível ocorrência de dormência nos dois primeiros meses após a colheita, em sementes de cultivares de arroz recentemente lançadas para o Piauí. Utilizou-se o delineamento experimental inteiramente casualizado com parcelas subdivididas, sendo as parcelas representadas pelas épocas após a colheita (5,20,35,50 e 65 dias) e as subparcelas pelas três cultivares, com sete repetições. Verificaram-se efeitos (P<0,05) das épocas após a colheita sobre a germinação e a dormência das sementes de todas as cultivares de arroz estudadas. Imediatamente após a colheita (cinco dias), as sementes das cultivares de arroz de sequeiro apresentaram uma percentagem de germinação superior a da cultivar de arroz irrigado, ocorrendo a perda natural da dormência aos 35 dias, nas sementes de arroz de sequeiro, e somente aos 50 dias, no caso do arroz irrigado. No geral, as sementes da cv. Caiapó tiveram o maior índice de germinação, enquanto as da cv. Diamante revelaram a maior percentagem de dormência.bitstream/item/35774/1/BP16.pd

Phantom Accretion by Black Holes and the Generalized Second Law of Thermodynamics

The accretion of a phantom fluid with non-zero chemical potential by black holes is discussed with basis on the Generalized Second Law of thermodynamics. For phantom fluids with positive temperature and negative chemical potential we demonstrate that the accretion process is possible, and that the condition guaranteeing the positiveness of the phantom fluid entropy coincides with the one required by Generalized Second Law. In particular, this result provides a complementary confirmation that cosmological phantom fluids do not need to have negative temperatures

Variscan shear zones and control of Sn-W, Au, U mineralizations in the Central-Iberian Zone in Portugal

[Resumo] Propoese urna síntese sobre a génese dos cisalhamentos regionais e estruturas secundárias associadas nas diferentes fases colisionais, para o sector restricto da Zona Centro-Ibérica (Z.C.!.) da orogenia hercínica. Adoptam-se os conceitos de RAMSAY (1980) e SANDERSON &MARCHINI (1984) para enquadrar, respectivamente, a tipologia e cinemática destes cisalhamentos. Esboçase um cenário geral da geometria e cinemática das estructuras na Z.C.!., concomitantemente, com a evolu~ao dos cisalhamentos tangenciais nas fases precocese com os cisalhamentos transcorrentes nas fases tardias do orógeno. No quadro da associa~ao espacial das mineralizag:>es de Sn-W, Au e U aos cisalhamentos, define-se o controlo estrutural destas mineraliza~oes e procede-se a tentativa de hierarquizar as referidas mineralizag:>es da Z.C.!., conectando-as as diferentes fases de deformaçao da orogenia hercínica[Abstract] The tipology and kinematic evolution of the shear zones and related secondary structures in the Central Iberian Zone (Variscan orogeny) are stablished on the basis of the concepts expressed, respectively, by RAMSAY (1980) and SANDERSON & MARCHINI (1984). The geometry and kinematics of these structures are linked to the evolution of nappes in the preliminary deformation phases and with transcurrent shearing in the later deformation phases. The structural control and the spatial relationship of Sn-W, Au and U mineralizations by these shears, is defined. For each her cynian deformations phase it is made an atempt of hierarchyzation of these C.I.Z. mineralizations

Many-nodes/many-links spinfoam: the homogeneous and isotropic case

I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular graphs, with an arbitrary number of links and nodes, and coherent states peaked on a homogeneous and isotropic geometry. This form of the amplitude can be applied for example to a dipole with an arbitrary number of links or to the 4-simplex given by the compete graph on 5 nodes. All the resulting amplitudes have the same support, independently of the graph used, in the large j (large volume) limit. This implies that they all yield the Friedmann equation: I show this in the presence of the cosmological constant. This result indicates that in the semiclassical limit quantum corrections in spinfoam cosmology do not come from just refining the graph, but rather from relaxing the large j limit.Comment: 8 pages, 4 figure

Coherent states, constraint classes, and area operators in the new spin-foam models

Recently, two new spin-foam models have appeared in the literature, both motivated by a desire to modify the Barrett-Crane model in such a way that the imposition of certain second class constraints, called cross-simplicity constraints, are weakened. We refer to these two models as the FKLS model, and the flipped model. Both of these models are based on a reformulation of the cross-simplicity constraints. This paper has two main parts. First, we clarify the structure of the reformulated cross-simplicity constraints and the nature of their quantum imposition in the new models. In particular we show that in the FKLS model, quantum cross-simplicity implies no restriction on states. The deeper reason for this is that, with the symplectic structure relevant for FKLS, the reformulated cross-simplicity constraints, in a certain relevant sense, are now \emph{first class}, and this causes the coherent state method of imposing the constraints, key in the FKLS model, to fail to give any restriction on states. Nevertheless, the cross-simplicity can still be seen as implemented via suppression of intertwiner degrees of freedom in the dynamical propagation. In the second part of the paper, we investigate area spectra in the models. The results of these two investigations will highlight how, in the flipped model, the Hilbert space of states, as well as the spectra of area operators exactly match those of loop quantum gravity, whereas in the FKLS (and Barrett-Crane) models, the boundary Hilbert spaces and area spectra are different.Comment: 21 pages; statements about gamma limits made more precise, and minor phrasing change