Symmetry breaking in a localized interacting binary Bose-Einstein condensate in a bichromatic optical lattice

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Chaotic thermalization in Yang-Mills-Higgs theory on a spacial lattice

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Localization of a Bose-Einstein-condensate vortex in a bichromatic optical lattice

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Localization of collisionally inhomogeneous condensates in a bichromatic optical lattice

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Localization of a Bose-Fermi mixture in a bichromatic optical lattice

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Matter-wave localization in a weakly perturbed optical lattice

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Triangular-lattice anisotropic dimerized Heisenberg antiferromagnet: Stability and excitations of the quantum paramagnetic phase

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Magnetic field induced lattice effects in a quasi-two-dimensional organic conductor close to the Mott metal-insulator transition

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Effect of magnesium addition on the vacancy-Mg binding free enthalpy in Al-Cr alloys

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Loading of praziquantel in the crystal lattice of solid lipid nanoparticles Studies by DSC and SAXS

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Enthalpy-entropy compensation based on isotherms of mango

Dados de equilíbrio da umidade da polpa de manga foram determinados utilizando-se o método estático gravimétrico. As isotermas de adsorção e dessorção foram obtidas na faixa de 30-70 ºC e as atividades de água (a w) de 0,02 a 0,97. A utilização do modelo de GAB nos resultados experimentais, através da análise de regressão não linear, proporcionou um bom ajuste entre os dados experimentais e os valores calculados. O calor isostérico de sorção foi estimado a partir dos dados de equilíbrio de sorção, utilizando-se a equação de Clausius-Clayperon. Notou-se que os calores isostéricos de sorção crescem com o aumento da temperatura e pode ser bem ajustado através de uma relação exponencial. A teoria da compensação entalpia-entropia foi aplicada às isotermas de sorção e gráficos deltaH versus deltaS forneceram as temperaturas isocinéticas, indicando um processo de sorção entalpicamente controlado.

Study of the enthalpy-entropy mechanism from water sorption of orange seeds (C. sinensis cv. Brazilian) for the use of agro-industrial residues as a possible source of vegetable oil production

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Vortex lattice of a long superconducting wire with a columnar defect

In the present work we study a long superconducting wire with a columnar defect in the presence of an applied magnetic field. The cross section of the cylinder is assumed to be circular. The field is taken uniform and parallel to the cylinder axis. We use the London theory to investigate the vortex lattice inside the wire. Although this theory is valid in the limit of low vortex density, that is, when the nearest neighbor vortex distance is much larger than the coherence length, we can obtain a reasonable qualitative description of lattice properties. We calculate: (1) the vortex lattice structure using the simulated annealing technique; (2) the magnetization curve as a function of the applied field.

Thermally activated dynamics in La2CuO4+delta: tilts of the CuO6 octahedra and interstitial O

An intense peak of the elastic energy loss versus temperature is found in La2CuO4 at 150 K (in the LTO phase), at a vibration frequency of similar to 280 Hz. From the dependence of the dissipation curve on frequency it is deduced that the relaxation rate has an activation enthalpy of 0.23 eV. The peak is ascribed to a thermally activated dynamics of the tilts of the CuO6 octahedra which form the La2CuO4 lattice, a fraction of which are supposed to be able to switch between energetically equivalent configurations. The peak is suppressed by interstitial O; this is explained by supposing that each interstitial atom can block several octahedra into a configuration that can accommodate the distortion due to its presence. Increasing the content of excess O, two new thermally activated processes develop, attributed to the hopping of interstitial O atoms which are isolated and which are paired or otherwise aggregated. The activation enthalpy for the diffusion of O at low values of 6 is 0.48 eV.

Luminescent properties and lattice defects correlation on zinc oxide

The ZnO luminescent properties are strongly influenced by the preparation method and they are principally related to electronic and crystalline structures. This work reports about the correlation among luminescence properties of ZnO, obtained from zinc hydroxycarbonate, and crystalline lattice defects, microstrain, as function of thermal treatment. The crystallite size increase and the qualitative microstrain, obtained by Williamson-Hall plots, decrease as function of temperature. The evolution of electronic defects is analyzed by luminescence spectroscopy based on energy of the electronic transitions. From excitation spectrum, it is verified two bands around 377 nm and 405 nm attributed to the transitions between valence-conduction bands and valence band to interstitial zinc level, respectively. The emission spectra of sample treated at 600 degreesC shows large band at 670 nm. However, the green emission around 530 nm is observed for samples treated at 900 degreesC. The intensities of excitation and emission bands are associated with the increase of the electronic defects that depend on the strain lattice decrease. The lowest strain lattice results on the best green luminescent properties of zinc oxide. (C) 2001 Elsevier B.V. Ltd. All rights reserved.