The identification of physical close galaxy pairs

A classification scheme for close pairs of galaxies is proposed. The scheme is motivated by the fact that the majority of apparent close pairs are in fact wide pairs in three-dimensional space. This is demonstrated by means of numerical simulations of random samples of binary galaxies and the scrutiny of the resulting projected and spatial separation distributions. Observational strategies for classifying close pairs according to the scheme are suggested. As a result, physical (i.e., bound and spatially) close pairs are identified.Comment: 16 pages, 5 figures, accepted for publication in The Astronomical Journal, added text corrections on proof

Anisotropy and percolation threshold in a multifractal support

Recently a multifractal object, $Q_{mf}$, was proposed to study percolation properties in a multifractal support. The area and the number of neighbors of the blocks of $Q_{mf}$ show a non-trivial behavior. The value of the probability of occupation at the percolation threshold, $p_{c}$, is a function of $\rho$, a parameter of $Q_{mf}$ which is related to its anisotropy. We investigate the relation between $p_{c}$ and the average number of neighbors of the blocks as well as the anisotropy of $Q_{mf}$

Environmental inversion using high-resolution matched-field processing

This paper considers the inversion of experimental field data collected with light receiving systems designed to meet operational requirements. Such operational requirements include system deployment in free drifting configurations and a limited number of acoustic receivers. A well-known consequence of a reduced spatial coverage is a poor sampling of the vertical structure of the acoustic field, leading to a severe ill-conditioning of the inverse problem and data to model cost function with a massive sidelobe structure having many local extrema. This causes difficulties to meta-heuristic global search methods, such as genetic algorithms, to converge to the true model parameters. In order to cope with this difficulty, broadband high-resolution processors are proposed for their ability to significantly attenuate sidelobes, as a contribution for improving convergence. A comparative study on simulated data shows that high-resolution methods did not outperform the conventional Bartlett processor for pinpointing the true environmental parameter when using exhaustive search. However, when a meta-heuristic technique is applied for exploring a large multidimensional search space, high-resolution methods clearly improved convergence, therefore reducing the inherent uncertainty on the final estimate. These findings are supported by the results obtained on experimental field data obtained during the Maritime Rapid Environmental Assessment 2003 sea trial. (c) 2007 Acoustical Society of America

Seleção de plantas em lavouras de café conilon no sul do Espírito Santo.

As lavouras de Conilon do Sul do Espírito Santo apresentam grande variabilidade genética, ainda não explorada nos trabalhos de melhoramento da Empresa Capixaba de Pesquisa, Assistência Técnica e Extensão Rural ? EMCAPER. O presente trabalho objetivou identificar plantas de café Conilon, com alta produção e qualidade de grãos na região Sul, para inclusão nos ensaios de competição com vistas a recomendação de novas variedades para os produtores capixabas. No primeiro ano foram selecionadas 391 plantas com bom potencial produtivo, tamanho do grão e uniformidade de maturação

Zoneamento agroclimático da cultura do feijoeiro para o Estado de Alagoas.

Neste estudo foi utilizado o modelo SARRA (Sistema de Análise Regional dos Riscos Agroclimáticos).bitstream/CNPAF/25034/1/comt_122.pd

Zoneamento agroclimático da cultura do feijoeiro para o Estado de Pernambuco.

Neste estudo foi utilizado o modelo SARRA (Sistema de Análise Regional dos Riscos Agroclimáticos).bitstream/CNPAF/25035/1/comt_123.pd

A checklist of digenean parasites (Platyhelminthes: Digenea) infecting molluscs and fishes in Portuguese waters (Northeast Atlantic)

The present work is a compilation of the digenean parasites infecting molluscs (gastropods and bivalves), crabs and fishes of the Atlantic coast of Portugal and the Archipelagos of Azores and Madeira, based on literature sources, including research conducted by the present authors. A total of 65 digenea taxa were found, belonging to 24 families, infecting gastropods, bivalves, shore crabs and fishes. The most representative families of digeneans were the Hemiuridae (11 taxa), followed by the Bucephalidae (5 taxa), Opecoelidae (5 taxa) and the Zoogonidae (5 taxa). Hosts, site of infection, sampling locality and life cycle strategy are given when available. Further fields of research on the digenean parasites are suggested.info:eu-repo/semantics/publishedVersio