Regeneração e multiplicação de germoplasma de milho (Zea mays L.) na Região Amazônica.

bitstream/item/57469/1/CPATU-PA204.pd

Dipole-induced vortex ratchets in superconducting films with arrays of micromagnets

We investigate the transport properties of superconducting films with periodic arrays of in-plane magnetized micromagnets. Two different magnetic textures are studied: a square array of magnetic bars and a close-packed array of triangular microrings. As confirmed by MFM imaging, the magnetic state of both systems can be adjusted to produce arrays of almost point-like magnetic dipoles. By carrying out transport measurements with ac drive, we observed experimentally a recently predicted ratchet effect induced by the interaction between superconducting vortices and the magnetic dipoles. Moreover, we find that these magnetic textures produce vortex-antivortex patterns, which have a crucial role on the transport properties of this hybrid system.Comment: 4 pages, 4 figure

Avaliação do estado nutricional de espécies componentes de sistema agroflorestais em solos de baixa fertilidade em Rondônia.

Este trabalho tem como objetivo avaliar o estado nutricional de espécies componentes de sistemas agroflorestais estabelecidos em solos de baixa fertilidade no Estado de Rondônia