1,316 research outputs found
Avaliação da qualidade do solo sob diferentes arranjos estruturais do eucalipto no sistema de integração lavoura-pecuária-floresta.
Onset of phase correlations in YBa2Cu3O{7-x} as determined from reversible magnetization measurements
Isofield magnetization curves are obtained and analyzed for three single
crystals of YBa2Cu3O{7-x}, ranging from optimally doped to very underdoped, as
well as the BCS superconductor Nb, in the presence of magnetic fields applied
both parallel and perpendicular to the planes. Near Tc, the magnetization
exhibits a temperature dependence \sqrt{M} [Ta(H)-T]^m. In accordance with
recent theories, we associated Ta(H) with the onset of coherent phase
fluctuations of the superconducting order parameter. For Nb and optimally doped
YBaCuO, Ta(H) is essentially identical to the mean-field transition line Tc(H).
The fitting exponent m=0.5 takes its mean-field value for Nb, and varies just
slightly from 0.5 for optimally doped YBaCuO. However, underdoped YBCO samples
exhibit anomalous behavior, with Ta(H)>Tc for H applied parallel to the c axis,
suggesting that the magnetization is probing a region of temperatures above Tc
where phase correlations persist. In this region, the fitting exponent falls in
the range 0.5 < m < 0.8 for H\parallel c, compared with m~0. for $H\parallel ab
planes. The results are interpreted in terms of an anisotropic pairing symmetry
of the order parameter: d-wave along the ab planes and s-wave along the c axis.Comment: 5 pages, 4 figure
Anomalous metamagnetic-like transition in a FeRh/FePt interface occurring at T120 K in the field-cooled-cooling curves for low magnetic fields
We report on the magnetic properties of a special configuration of a FeRh
thin film. An anomalous behavior on the magnetisation vs. temperature was
observed when low magnetic fields are applied in the plane of a thin layer of
FeRh deposited on ordered FePt. The anomalous effect resembles a
metamagnetic transition and occur only in the field-cooled-cooling
magnetisation curve at temperatures near 120 K in samples without any heat
treatment.Comment: 7 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1008.195
Avaliação da fertilidade de um Latossolo Vermelho-Amarelo em diferentes profundidades em sistema de integração Lavoura-Pecuária-Floresta (iLPF).
Influência de aléias de leguminosas arbóreas na infestação de bicho-mineiro em cafeeiro.
O bicho-mineiro, Leucoptera coffeella (Guérin - Mèneville, 1842) (Lepidoptera: Lyonetiidae), é talvez a principal praga do cafeeiro (Coffea spp.) na atualidade, principalmente nas regiões de temperaturas mais elevadas e de maior déficit hídrico. Vários estudos indicam que a abundância e diversidade de insetos dentro de um campo podem estar intimamente relacionadas com a natureza da vegetação circundante. Considerando o exposto, foi objetivo deste trabalho observar o efeito de espécies de leguminosas arbóreas utilizadas como quebra-ventos (aléias) sobre os aspectos fitossanitários do cafeeiro. As leguminosas utilizadas foram: o Guandu (Cajanus cajan Millsp.), Bracatinga (Mimosa scabrella Benth.), Leucena (Leucaena leucocephala (Lam.) De Wit) e Acácia (Acacia mangium Willd.), plantadas perpendiculares ao sentido dos ventos predominantes. Os resultados parciais, obtidos em 2003, 2004, 2005 e 2006, mostram que a menor porcentagem de folhas com minas intactas foi observada nos cafeeiros sob Leucena e Guandu e também a menor porcentagem de minas predadas. Os cafeeiros sob Leucena e Guandu apresentaram nível de controle (NC) para o bicho-mineiro (30% de folhas minadas sem sinais de predação) no final de agosto enquanto que aqueles sob Acácia e Bracatinga foram semelhantes à testemunha e apresentaram NC bem mais cedo, no mês de junho
Sustainable Horticulture: A bibliometric Study
This paper examines the scientific researches regarding "sustainable horticulture" to identify research flows with potential for future investigation. Through a bibliometric and content analysis for the 2011-2015 periods and the 2016 first semester, 12 articles, according and relevant to the theme, were selected. The results obtained from the analysis demonstrated the importance of the subject for both academic research and for the practice, since it elucidated scientific production and trends, impact factor, relevant scientific periodicals, contribution by countries and its institutions, methods and research tools, keywords. It stands out that the theme "sustainable horticulture" is used in most cases to address only the environmental dimension and, in a few cases, in the economic and social dimensions. Based in the analysis of the keywords, the terms production, systems and sustainability formed the main research clusters, attracting great attention during the study period
Implantação de pastagem de Braquiária brizanta consorciado com diferentes cultivares de sorgo.
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