25 research outputs found
Effect of Order-Parameter Suppression on Scattering by Isolated Impurities in Asymmetric Bands
The single-impurity problem in d-wave superconductors with asymmetric bands
is discussed. The effect of local order parameter suppression near the impurity
is to shift the quasiparticle resonance. Contrary to previous work [A. Shnirman
et al., Phys. Rev. B 60, 7517 (1999)] we find that the direction of the shift
is not universally towards the strong scattering limit.Comment: 2 pages, 1 figure, proceedings for M2S-HTSC-V
Electronic Properties of Two-Dimensional Carbon
We present a theoretical description of the electronic properties of graphene
in the presence of disorder, electron-electron interactions, and particle-hole
symmetry breaking. We show that while particle-hole asymmetry, long-range
Coulomb interactions, and extended defects lead to the phenomenon of
self-doping, local defects determine the transport and spectroscopic
properties. Our results explain recent experiments in graphitic devices and
predict new electronic behavior.Comment: 4 pages, 5 figures. The paper was originally submitted on May, 12th,
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Viabilidade técnico-econômica do uso de diferentes tecnologias de iluminação para indução de fotoperíodo na produção de mudas de crisântemo Technical and economical viability of distinct illumination technologies applied to photoperiod induction in chrysanthemum production
Em função de suas características fisiológicas, as mudas de crisântemo necessitam de luz suplementar para evitar formação de botão floral. Isto é feito no período noturno. O presente trabalho visou a analisar a viabilidade técnico-econômica de substituir-se a atual tecnologia de iluminação artificial utilizada pelos produtores (lâmpadas incandescentes) para efeito de indução de fotoperíodo em ambiente protegido, pela tecnologia de lâmpadas de descarga, com o objetivo de reduzir o consumo de energia elétrica utilizada no processo. As lâmpadas de descarga possuem maior vida útil e apresentam menor consumo de energia quando comparadas às lâmpadas incandescentes. Os resultados das análises permitem concluir que a lâmpada fluorescente compacta integrada amarela, de 23 W, é a que apresenta viabilidade técnica e econômica para tal substituição.<br>Physiological characteristics of chrysanthemum nurseries require extra light supply to prevent buds production. That extra illumination is carried during night period. This research aimed to analyze the technical and economical viability associated to the substitution of conventional incandescent lamps used by the producers to discharge lamps to induce photoperiod, aiming electricity cost reduction in protected environment. Discharge lamps are more efficient, exhibit lower consumption and longer life when compared to the incandescent ones. The results of the analysis allow concluding that the yellow fluorescent compact integrated 23 W lamp turned to be technical and economically viable for the proposed substitution