Emergence of turbulence in an oscillating Bose-Einstein condensate

We report on the experimental observation of vortices tangle in an atomic BEC of Rb-87 atoms when an external oscillatory perturbation is introduced in the trap. The vortices tangle configuration is a signature of the presence of a turbulent regime in the cloud. We also show that this turbulent cloud has suppression of the aspect ratio inversion typically observed in quantum degenerate bosonic gases during free expansion. Instead, the cloud expands keeping the ratio between their axis constant. Turbulence in atomic superfluids may constitute an alternative system to investigate decay mechanisms as well as to test fundamental theoretical aspects in this field.Comment: accepted for Phys. Rev. Let

Análise de inibidores da fermentação em licor resultante do pré-tratamento de eucalipto para produção de etanol.

Resumo

Análise da relação siringila : guaiacila por cromatografia gasosa acoplado a espectrometria de massa.

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Avaliação das condições de pré-tratamento alcalino do Eucalyptus.

Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos

Spectropolarimetry of the Luminous Narrow-Line Seyfert Galaxies IRAS 20181-2244 and IRAS 13224-3809

We observed the narrow-line Seyfert 1 galaxies IRAS 20181-2244 and IRAS 13324-3809 with a new spectropolarimeter on the RC spectrograph at the CTIO 4m telescope. Previously it had been suggested that IRAS 20181-2244 was a Type 2 QSO and thus might contain an obscured broad-line region which could be detected by the presence of broad Balmer lines in the polarized flux. We found the object to be polarized at about 2%, and constant with wavelength, (unlike most narrow-line Seyfert 1s), but with no evidence of broad Balmer lines in polarized flux. The spectropolarimetry indicates that the scattering material is inside the BLR. IRAS 13224-3809, notable for its high variability in X-ray and UV wavelengths, has a low polarization consistent with a Galactic interstellar origin.Comment: 19 pages using (AASTEX) aaspp4.sty and 5 postscript figures To be published in the Astrophysical Journa

Nanocellulose filled biobased polyurethane foams.

In this paper, nanocellulose (NC) dispersed in glycerin was incorporated into polyurethane (PU) biobased foams, using castor oil and glycerin, in a ratio of 3:1, as a biopolyol, produced by free-rise pouring method. Firstly, the morphologicals properties, measureds by scanning electronic microscopy (SEM) images, were investigated and, after, the apparent density and compressives properties were measureds. The results indicated efficience in the preparation method for the biofoams and the filled foams presented a decrease in the cellular anisotropy and linear cell density and an increase in cell diameter, with a more homogenous cell structure. These morphologicals properties justify the modifications caused by the fillers in the biofoams, a larger cell, with less orientation, caused a decrease in the values of the apparent density and consequently lower values in compressive mechanical properties

Irrigação e fertirrigação na cultura de citros.

Sistemas de irrigação; Necessidade hídrica dos citros; Transpiração da cultura; Absorção de água pelo sistema radicular sob irrigação; Manejo da irrigação; Fertirrigação; Necessidades nutricionais; Manejo da fertirrigação