Maxwell-Chern-Simons vortices in a CPT-odd Lorentz-violating Higgs Electrodynamics

We have studied BPS vortices in a CPT-odd and Lorentz-violating Maxwell-Chern-Simons-Higgs (MCSH) electrodynamics attained from the dimensional reduction of the Carroll-Field-Jackiw-Higgs model. The Lorentz-violating parameter induces a pronounced behavior at origin (for the magnetic/electric fields and energy density) which is absent in the MCSH vortices. For some combination of the Lorentz-violating coefficients there always exist a sufficiently large winding number $n_{0}$ such that for all $$ the magnetic field flips its signal, yielding two well defined regions with opposite magnetic flux. However, the total magnetic flux remains quantized and proportional to the winding number.Comment: Revtex style, 8 page

Balanço dos aspectos técnicos do cultivo do nim no Brasil.

Silvicultura; Química dos produtos da copa; Melhoramento genético; Madeira; Invasão biológica.bitstream/item/47045/1/Doc208.pd

Teores foliares de nutrientes em plantios de Nim nos Estados do Paraná e São Paulo.

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Order and Disorder in AKLT Antiferromagnets in Three Dimensions

The models constructed by Affleck, Kennedy, Lieb, and Tasaki describe a family of quantum antiferromagnets on arbitrary lattices, where the local spin S is an integer multiple M of half the lattice coordination number. The equal time quantum correlations in their ground states may be computed as finite temperature correlations of a classical O(3) model on the same lattice, where the temperature is given by T=1/M. In dimensions d=1 and d=2 this mapping implies that all AKLT states are quantum disordered. We consider AKLT states in d=3 where the nature of the AKLT states is now a question of detail depending upon the choice of lattice and spin; for sufficiently large S some form of Neel order is almost inevitable. On the unfrustrated cubic lattice, we find that all AKLT states are ordered while for the unfrustrated diamond lattice the minimal S=2 state is disordered while all other states are ordered. On the frustrated pyrochlore lattice, we find (conservatively) that several states starting with the minimal S=3 state are disordered. The disordered AKLT models we report here are a significant addition to the catalog of magnetic Hamiltonians in d=3 with ground states known to lack order on account of strong quantum fluctuations.Comment: 7 pages, 2 figure

Toxoplasma gondii: serological study in pigs slaughtered in Portugal

Toxoplasma gondii has a worldwide distribution and usually is not detected macroscopically by traditional meat inspection methods. The aim of this study was to assess the seroprevalence of Toxoplasma gondii in slaughter swine using a modified direct agglutination method (MAT) (Toxo-Screen DA, Biomérieux® SA). No positive results were obtained in sera from 337 animals from 12 intensive production farms tested in duplicate at the dilutions of 1:20 and 1:40. The estimated seroprevalence was 0%. The 95% confidence intervals ranged from 0 to 21.8% within batches, and 0 to 1.1% of all animals. In 10 of the 12 farms, Toxoplasma seroprevalence was below 7% (\u3e99% confidence level). In the remaining two farms, the sampling fraction was too small to distinguish a population with prevalence of 7% from a disease-free population. Our findings suggest that Toxoplasma seroprevalence in intensive pig farms is likely to be below 7%. However, selection of farms was not random, so further studies are required to allow making inferences for all intensive pig farms in the centre and north of Portugal

Optical doping and damage formation in AIN by Eu implantation

AlN films grown on sapphire were implanted with 300 keV Eu ions to fluences from 3×1014 to 1.4×1017 atoms/cm2 in two different geometries: “channeled” along the c-axis and “random” with a 10° angle between the ion beam and the surface normal. A detailed study of implantation damage accumulation is presented. Strong ion channeling effects are observed leading to significantly decreased damage levels for the channeled implantation within the entire fluence range. For random implantation, a buried amorphous layer is formed at the highest fluences. Red Eu-related photoluminescence at room temperature is observed in all samples with highest intensities for low damage samples (low fluence and channeled implantation) after annealing. Implantation damage, once formed, is shown to be stable up to very high temperatures.FCT - POCI/FIS/57550/2004FCT - PTDC/FIS/66262/2006FCT - PTDC/CTM/100756/200