Remarks on Charged Vortices in the Maxwell-Chern-Simons Model

We study vortex-like configuration in Maxwell-Chern-Simons Electrodynamics. Attention is paid to the similarity it shares with the Nielsen-Olesen solutions at large distances. A magnetic symmetry between a point-like and an azimuthal-like current in this framework is also pointed out. Furthermore, we address the issue of a neutral and spinless particle interacting with a charged vortex, and obtain that the Aharonov-Casher-type phase depends upon mass and distance parameters.Comment: New refs. added. Version accepted for publication in Phys. Lett.

Manifestations of fine features of the density of states in the transport properties of KOs2O6

We performed high-pressure transport measurements on high-quality single crystals of KOs2O6, a beta-pyrochlore superconductor. While the resistivity at high temperatures might approach saturation, there is no sign of saturation at low temperatures, down to the superconducting phase. The anomalous resistivity is accompanied by a nonmetallic behavior in the thermoelectric power (TEP) up to temperatures of at least 700 K, which also exhibits a broad hump with a maximum at 60 K. The pressure influences mostly the low-energy electronic excitations. A simple band model based on enhanced density of states in a narrow window around the Fermi energy (EF) explains the main features of this unconventional behavior in the transport coefficients and its evolution under pressure

On the Derivative Expansion at Finite Temperature

In this short note, we indicate the origin of nonanalyticity in the method of derivative expansion at finite temperature and discuss some of its consequences.Comment: 7 pages, UR-1363, ER40685-81

Analysis of grassland degradation in Zona da Mata, MG, Brazil, based on NDVI time series data with the integration of phenological metrics.

Abstract: There is currently a lot of interest in determining the state of Brazilian grasslands. Governmental actions and programs have recently been implemented for grassland recovery in Brazilian states, with the aim of improving production systems and socioeconomic indicators. The aim of this study is to evaluate the vegetative growth, temporal vigor, and long-term scenarios for the grasslands in Zona da Mata, Minas Gerais State, Brazil, by integrating phenological metrics. We used metrics derived from the normalized difference vegetation index (NDVI) time series from moderate resolution imaging spectroradiometer (MODIS) data, which were analyzed in a geographic information system (GIS), using multicriteria analysis, the analytical hierarchy process, and a simplified expert system (ESS). These temporal metrics, i.e., the growth index (GI) for 16-day periods during the growing season; the slope; and the maximum, minimum, and mean for the time series, were integrated to investigate the grassland vegetation conditions and degradation level. The temporal vegetative vigor was successfully described using the rescaled range (R/S statistic) and the Hurst exponent, which, together with the metrics estimated for the full time series, imagery, and field observations, indicated areas undergoing degradation or areas that were inadequately managed (approximately 61.5%). Time series analysis revealed that most grasslands showed low or moderate vegetative vigor over time with long-term persistence due to farming practices associated with burning and overgrazing. A small part of the grasslands showed high and sustainable plant densities (approximately 8.5%). A map legend for grassland management guidelines was developed using the proposed method with remote sensing data, which were applied using GIS software and a field campaign

Effect of Impurity Scattering on the Nonlinear Microwave Response in High-Tc Superconductors

We theoretically investigate intermodulation distortion in high-Tc superconductors. We study the effect of nonmagnetic impurities on the real and imaginary parts of nonlinear conductivity. The nonlinear conductivity is proportional to the inverse of temperature owing to the dependence of the damping effect on energy, which arises from the phase shift deviating from the unitary limit. It is shown that the final-states interaction makes the real part predominant over the imaginary part. These effects have not been included in previous theories based on the two-fluid model, enabling a consistent explanation for the experiments with the rf and dc fields

Um cenário de balanço do carbono para Áreas de Preservação Permanentes em mesorregiões leiteiras usando SIG e dados de sensoriamento remoto.

O objetivo deste trabalho foi mapear algumas categorias de Áreas de Preservação Permanentes (APP), com base no Código Florestal de 1965, destinadas à recuperação por regeneração natural de florestas semidecíduas nas mesorregiões Zona da Mata e Campo das Vertentes, Minas Gerais, e a partir disto estabelecer qual é o impacto do emprego das APP?s sobre as áreas de pastagens e subsequente sequestro de carbono. Assim, o cenário de carbono fixo pelas florestas naturais e seu balanço foi considerado como um importante fator para a manutenção de ecossistemas naturais, que posteriormente poderá ser comparado com cenários para o novo código florestal. A partir das informações altimétricas de modelos digitais de elevação (MDE), foi possível extrair dados morfométricos e morfológicos para estimar a APP. Foram utilizadas imagens MODIS / Terra para a extração de áreas de pastagens com o uso de índices de vegetação NDVI para o cruzamento com as APP?s estimadas. Num cenário linear e determinístico de implantação das APP?s em substituição às áreas de pastagens haveria a retração dessas áreas ou impacto de aproximadamente 12% na produção de leite do Campo das Vertentes e 21,5% na produção de leite da Zona da Mata, com subsequente fixação de 48 milhões de toneladas de carbono até o clímax florestal, quando da implantação de florestas semideciduais, e com balanço positivo de 2 ton/ha/ano de carbono fixo, enquanto a pecuária produz 1 ton/ha/ano, se bem manejadas, revelando-se equilíbrio