Polarizabilities of the 87Sr Clock Transition

In this paper, we propose an in-depth review of the vector and tensor polarizabilities of the two energy levels of the 87Sr clock transition whose measurement was reported in [P. G. Westergaard et al., Phys. Rev. Lett. 106, 210801 (2011)]. We conduct a theoretical calculation that reproduces the measured coefficients. In addition, we detail the experimental conditions used for their measurement in two Sr optical lattice clocks, and exhibit the quadratic behaviour of the vector and tensor shifts with the depth of the trapping potential and evaluate their impact on the accuracy of the clock

Measurement of the Blackbody Radiation Shift of the 133Cs Hyperfine Transition in an Atomic Fountain

We used a Cs atomic fountain frequency standard to measure the Stark shift on the ground state hyperfine transiton frequency in cesium (9.2 GHz) due to the electric field generated by the blackbody radiation. The measures relative shift at 300 K is -1.43(11)e-14 and agrees with our theoretical evaluation -1.49(07)e-14. This value differs from the currently accepted one -1.69(04)e-14. The difference has a significant implication on the accuracy of frequency standards, in clocks comparison, and in a variety of high precision physics tests such as the time stability of fundamental constants.Comment: 4 pages, 2 figures, 2 table

Levantamento da ocorrência de Sternechus subsignatus no Rio Grande do Sul.

bitstream/item/133935/1/ID43416-1990-1991sojaresultados-p86-94.pdfTrabalhos apresentados na XIX Reunião de Pesquisa de Soja da Região Sul, Pelotas, 1991

Evolução dos defeitos da soja comercial durante o armazenamento em função da infestação de percevejos na lavoura.

O objetivo deste trabalho foi determinar a evolução dos defeitos da soja comercial durante 360 dias de armazenamento, em função da infestação de percevejos na lavoura

Avaliação de impactos econômicos sociais e ambientais de algumas tecnologias geradas pela Embrapa Trigo.

bitstream/CNPT-2010/40708/1/p-do90.pd