Proposed Spontaneous Generation of Magnetic Fields by Curved Layers of a Chiral Superconductor

We demonstrate that two-dimensional chiral superconductors on curved surfaces spontaneously develop magnetic flux. This geometric Meissner effect provides an unequivocal signature of chiral super- conductivity, which could be observed in layered materials under stress. We also employ the effect to explain some puzzling questions related to the location of zero-energy Majorana modes

Internal Josephson Oscillations for Distinct Momenta Bose-Einstein Condensates

The internal Josephson oscillations between an atomic Bose-Einstein condensate (BEC) and a molecular one are studied for atoms in a square optical lattice subjected to a staggered gauge field. The system is described by a Bose-Hubbard model with complex and anisotropic hopping parameters that are different for each species, i.e., atoms and molecules. When the flux per plaquette for each species is small, the system oscillates between two conventional zero-momentum condensates. However, there is a regime of parameters in which Josephson oscillations between a vortex-carrying atomic condensate (finite momentum BEC) and a conventional zero-momentum molecular condensate may be realized. The experimental observation of the oscillations between these qualitatively distinct BEC's is possible with state-of-the-art Ramsey interference techniques.Comment: 8 pages, 6 figure

Avaliação da transferência de metano no sentido gás-líquido e da capacidade de suprimento da desnitrificação biológica de esgoto sanitário com doadores endógenos de elétrons (metano e sulfeto de hidrogênio

Este trabalho apresenta uma avaliação da capacidade de desnitrificação biológica de esgoto sanitário através de fontes endógenas de elétrons (metano e sulfeto de hidrogênio) em um sistema de tratamento que associa em série processos biológicos anaeróbios e aeróbios. O metano presente no biogás produzido num reator UASB pode ser utilizado na etapa de desnitrificação através de sua transferência para a fase líquida. Essa transferência, porém, apresenta limitações que podem comprometer seu uso como única fonte de elétrons. Por esse motivo, uma das etapas desse estudo objetivou a avaliação da capacidade de transferência de metano no sentido gás-líquido. Os resultados demonstram o incremento da capacidade padrão de transferência (STR) com o aumento da taxa de aplicação de biogás. Contudo, esse incremento não se mostrou proporcional, o que implica na redução da eficiência padrão de transferência (STE). Na segunda etapa do estudo foi simulada a utilização de metano e de sulfeto de hidrogênio produzidos na etapa anaeróbia como doadores de elétrons para a desnitrificação biológica de esgoto sanitário num sistema anaeróbio aeróbio em sete cenários diferentes onde foram permutados fatores importantes ao processo. Em todos os cenários foram consideradas as relações estequiométricas da via desnitrificante. Se considerado o fornecimento de todo o metano recuperado como biogás à desnitrificação foram alcançados efluentes finais com teores nulos de N-NO3-. Essa consideração, no entanto, leva à superestimar o potencial de utilização desse doador de elétrons. A utilização do metano e sulfeto de hidrogênio dissolvidos no efluente do reator UASB e do metano recuperado como biogás e efetivamente fornecido ao sistema apresentou capacidade de remoção de 13,8 mg.L-1 de N-NO3-, 8,44 mg.L-1 de N-NO3- e 6,42 mg.L-1 de N-NO3-. Isso representa eficiências de remoção de 49,1%, 30,0% e 22,9% de todo N-NO3- do sistema, respectivamente, estando a capacidade de anulação dos teores de nitrato no efluente condicionada à utilização em conjunto desses doadores de elétrons. Mesmo que as relações C/N e S/N reais sejam maiores que as estequiométricas, e possam levar a limitações da capacidade de sustentação da desnitrificação biológica com fontes endógenas de elétrons, essas fontes podem ser utilizadas de forma a reduzir a necessidade de doadores exógenos de elétrons e, consequentemente, os custos de tratamento, potencializando a promoção da utilização dessa tecnologia no tratamento de efluentes sanitários

Interaction-induced chiral p_x \pm i p_y superfluid order of bosons in an optical lattice

The study of superconductivity with unconventional order is complicated in condensed matter systems by their extensive complexity. Optical lattices with their exceptional precision and control allow one to emulate superfluidity avoiding many of the complications of condensed matter. A promising approach to realize unconventional superfluid order is to employ orbital degrees of freedom in higher Bloch bands. In recent work, indications were found that bosons condensed in the second band of an optical chequerboard lattice might exhibit p_x \pm i p_y order. Here we present experiments, which provide strong evidence for the emergence of p_x \pm i p_y order driven by the interaction in the local p-orbitals. We compare our observations with a multi-band Hubbard model and find excellent quantitative agreement

Magnetic susceptibility anisotropies in a two-dimensional quantum Heisenberg antiferromagnet with Dzyaloshinskii-Moriya interactions

The magnetic and thermodynamic properties of the two-dimensional quantum Heisenberg antiferromagnet that incorporates both a Dzyaloshinskii-Moriya and pseudo-dipolar interactions are studied within the framework of a generalized nonlinear sigma model (NLSM). We calculate the static uniform susceptibility and sublattice magnetization as a function of temperature and we show that: i) the magnetic-response is anisotropic and differs qualitatively from the expected behavior of a conventional easy-axis QHAF; ii) the Neel second-order phase transition becomes a crossover, for a magnetic field B perpendicular to the CuO(2) layers. We provide a simple and clear explanation for all the recently reported unusual magnetic anisotropies in the low-field susceptibility of La(2)CuO(4), L. N. Lavrov et al., Phys. Rev. Lett. 87, 017007 (2001), and we demonstrate explicitly why La(2)CuO(4) can not be classified as an ordinary easy-axis antiferromagnet.Comment: 6 pages, 3 figures, Revtex4, accepted for publication in Phys. Rev.

Kounis Syndrome Associated With Selective Anaphylaxis to Cefazolin.

info:eu-repo/semantics/publishedVersio

Energy resource management under the influence of the weekend transition considering an intensive use of electric vehicles

Energy resource scheduling is becoming increasingly important, as the use of distributed resources is intensified and of massive electric vehicle is envisaged. The present paper proposes a methodology for day-ahead energy resource scheduling for smart grids considering the intensive use of distributed generation and Vehicle-to-Grid (V2G). This method considers that the energy resources are managed by a Virtual Power Player (VPP) which established contracts with their owners. It takes into account these contracts, the users' requirements subjected to the VPP, and several discharge price steps. The full AC power flow calculation included in the model takes into account network constraints. The influence of the successive day requirements on the day-ahead optimal solution is discussed and considered in the proposed model. A case study with a 33-bus distribution network and V2G is used to illustrate the good performance of the proposed method

Natural variability of lotic Mediterranean ecosystems or wildfire perturbations: who will win?

This study evaluates the impacts of wildfires in lotic Mediterranean ecosystems. It was carried out at Monchique ridge after big wildfires occurred during 2002 and 2003. Deferential impacts were evaluated comparing historical results obtained before the wildfires (1999 and 2001), with the post fire ones (2006 and 2007). Physical and chemical parameters of the water, habitat morphology, diatoms, macrophytes, macroinvertebrates and fishes were evaluated at 10 collecting places, before and after wildfires. High recovering rates were observed to the vegetation, but it is still possible to found fire impacts over macrophytes and river morphology. Wildfires, contributed to canopy decrease and, consequently to the growth of plants that usually are controlled by shadow. As a result, vegetation biodiversity tend to increase. River banks tend also to be invaded by terrestrial plants. Higher post fires recover rates were observed to the more aquatic communities (diatoms, macroinvertebrates and fishes). For those communities, comparing spring situations before and after the fires no substantial differences were observed. Sometimes differences between consecutive years are even higher. So it can be concluded that magnitude of wildfire impacts is less than the natural inter-annual variability of Mediterranean rivers. Long-term effects of forest fires, resulting from large woody debries, were also detected by morphological alterations, like debries dams. Habitat diversity increase and impacts on aquatic communities are expected