Chaotic Interaction of Langmuir Solitons and Long Wavelength Radiation

In this work we analyze the interaction of isolated solitary structures and ion-acoustic radiation. If the radiation amplitude is small solitary structures persists, but when the amplitude grows energy transfer towards small spatial scales occurs. We show that transfer is particularly fast when a fixed point of a low dimensional model is destroyed.Comment: LaTex + 4 eps file

Scaling Invariance in a Time-Dependent Elliptical Billiard

We study some dynamical properties of a classical time-dependent elliptical billiard. We consider periodically moving boundary and collisions between the particle and the boundary are assumed to be elastic. Our results confirm that although the static elliptical billiard is an integrable system, after to introduce time-dependent perturbation on the boundary the unlimited energy growth is observed. The behaviour of the average velocity is described using scaling arguments

Diagnóstico tecnológico e qualitativo das unidades produtoras de polpa do estado do Piauí.

Objetivando conhecer a situação da produção de polpa congelada do Estado do Piauí, foram realizadas ações que contemplaram a aplicação de um questionário aos produtores e a coleta de amostras de polpa de acerola, cajá e caju, para avaliação da qualidade química, físico-química e microbiológica.bitstream/CNPAT-2010/11939/1/Pa-058.pd

Magentically-Induced Lattice Distortions and Ferroelectricity in Magnetoelectric GdMnO3

In this work we investigate the magnetic field dependence of Ag octahedra rotation (tilt) and B2g symmetric stretching modes frequency at different temperatures. Our field-dependent Raman investigation at 10K is interpreted by an ionic displacive nature of the magnetically induced ferroelectric phase transition. The frequency change of the Ag tilt is in agreement with the stabilization of the Mn-Gd spin arrangement, yielding the necessary conditions for the onset of ferroelectricity on the basis of the inverse Dzyaloshinskii-Moriya interaction. The role of the Jahn-Teller cooperative interaction is also evidenced by the change of the B2g mode frequency at the ferroelectric phase transition. This frequency change allows estimating the shift of the oxygen position at the ferroelectric phase transition and the corresponding spontaneous polarization of 480 {\mu}C/m2, which agrees with earlier reported values in single crystals. Our study also confirms the existence of a large magnetic hysteresis at the lowest temperatures, which is a manifestation of magnetrostiction.Comment: 5 pages, 3 figure

Uso de fungicidas e óleo de Piper aducun (dilapiol) para o controle de Colletotrichum musae.

A banana está entre as frutas mais produzidas e consumidas no Brasil. A antracnose (Colletotrichum musae) é a principal doença pós-colheita em frutos, porém, a infecção inicia no campo. O controle da antracnose é difícil, e o estudo de produtos químicos e alternativos que reduzam as infecções e seu progresso nos frutos é importante no manejo da doença

Influence of the soil on sensorial characteristics of Petit Verdot tropical wines from the Northeast of Brazil.

The objective of this work was to evaluate Petit Verdot varietal wines elaborate from grapes of vines cultivated in three types of soils, sandy, gravelly and clayey, different on physical and chemical characteristics, being sandy and clayey argisoils and gravelly cambosoil, by enologists