High-field Electron Spin Resonance of Cu_{1-x}Zn_{x}GeO_{3}

High-Field Electron Spin Resonance measurements were made on powder samples of Cu_{1-x}Zn_{x}GeO_{3} (x=0.00, 0.01, 0.02, 0.03 and 0.05) at different frequencies (95, 110, 190, 220, 330 and 440 GHz) at low temperatures. The spectra of the doped samples show resonances whose positions are dependent on Zn concentration, frequency and temperature. The analysis of intensity variation of these lines with temperature allows us to identify them as originating in transitions within states situated inside the Spin Peierls gap. A qualitative explanation of the details of the spectra is possible if we assume that these states in the gap are associated with "loose" spins created near the Zn impurities, as recently theoreticaly predicted. A new phenomenon of quenching of the ESR signal across the Dimerized to Incommensurate phase-boundary is observed.Comment: 4 pages, 5 ps figures in the text, submitted to Phys. Rev. Let

Complex networks generated by the Penna bit-string model: emergence of small-world and assortative mixing

The Penna bit-string model successfully encompasses many phenomena of population evolution, including inheritance, mutation, evolution, and aging. If we consider social interactions among individuals in the Penna model, the population will form a complex network. In this paper, we first modify the Verhulst factor to control only the birth rate, and introduce activity-based preferential reproduction of offspring in the Penna model. The social interactions among individuals are generated by both inheritance and activity-based preferential increase. Then we study the properties of the complex network generated by the modified Penna model. We find that the resulting complex network has a small-world effect and the assortative mixing property

Ação microbiológica de filme de acetato com óleos essenciais em queijo coalho.

Resumo: As embalagens biodegradáveis têm sido amplamente exploradas como alternativas para substituição das embalagens convencionais. Estudos vêm sendo direcionados visando não somente a proteção, mas também a interação com o produto. Em alimentos as embalagens ativas atuam como barreira a agentes externos, contribuindo com uma melhor qualidade do produto e prolongando a vida de prateleira. A incorporação de substâncias antimicrobianas em embalagens é uma estratégia para solucionar o problema da contaminação microbiana em alimentos

Near--K-edge double and triple detachment of the F- negative ion: observation of direct two-electron ejection by a single photon

Double and triple detachment of the F-(1s2 2s2 2p6) negative ion by a single photon have been investigated in the photon energy range 660 to 1000 eV. The experimental data provide unambiguous evidence for the dominant role of direct photo-double-detachment with a subsequent single-Auger process in the reaction channel leading to F2+ product ions. Absolute cross sections were determined for the direct removal of a (1s+2p) pair of electrons from F- by the absorption of a single photon

Ação microbiológica de filme de acetato com óleos essenciais em queijo coalho.

Blucher Food Science Proceedings, v.1, n.1, nov. 2014

Efeito de fungicidas e inseticidas em sementes peletizadas de sorgo.

Edição dos resumos do 18º Congresso Brasileiro de Sementes, 2013, Florianópolis

Uma nova espécie de Tripartiella (Ciliophora: Trichodinidae) em Aequidens tetramerus da região Norte do Brasil.

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