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 $Q_{mf}$

Cartografia ao milionésimo dos solos dos municípios brasileiros utilizando o módulo SCarta do SPRING e proposta de acesso para a Internet.

Os Sistemas de Informação Geográfica (SIG) promoveram uma revolução nas operações de armazenamento e manipulação de informações espaciais e a Internet fomenta a atividade de disseminação desse tipo de informação para um público mais numeroso, heterogêneo e com diferentes interesses.bitstream/item/11840/1/comtec91.pd

Soil management: The key to soil quality and sustainable agriculture

Today, after the International Year of Soils in 2015 and the proclamation by the International Union of Soil Sciences of the International Decade of Soils 2015-2020, much attention is paid to soil quality. Often used interchangeably, both terms, soil quality and soil health, refer to dynamic soil properties such as soil organic matter or pH, while soil quality also includes inherent soil properties such as texture or mineral composition. However, it is the dynamic or manageable properties that adequate soil management can influence and thus contribute to a well-functioning soil environment capable to deliver the soil-mediated provisioning, regulating and supporting ecosystem services and soil functions. This contribution intends to highlight the key principles of sustainable soil management and provide evidence that they are compliant with a productive, resource efficient and ecologically friendly agriculture. Paradoxically, and despite benefitting from good soil quality, agriculture itself when based on conventional, especially intensive tillage-based soil management practices contributes decisively to soil degradation and to several of the soil threats as identified by the Soil Thematic Strategy, being soil erosion and soil organic matter decline the most notorious ones. To mitigate soil degradation, the European Union’s Common Agricultural Policy has introduced conservation measures, mainly through cross-compliance measures supposed to guarantee minimum soil cover, to limit soil erosion and to maintain the levels of soil organic matter. However, it remains unclear to what extent EU member states apply these ‘Good Agricultural and Environmental Condition’ (GAEC) measures to their utilized agricultural areas. Effective and cost-efficient soil management systems able to conserve or to restore favourable soil conditions, to minimize soil erosion and to invert soil organic matter and soil biodiversity decline and improve soil structure are those capable to mimic as close as possible natural soil conditions while producing food, feed, fibre and fuel. This means to establish and manage crops while disturbing the soil as least as possible, to maintain the soil permanently covered with plants or their residues and to allow for a diversity of plants either in rotation or in association. These principles also known as Conservation Agriculture have shown to be the most promising approach for a sustainable production intensification and proven to work in a wide range of agro-ecological conditions. Although adopted already on more than 150 Mha worldwide, in Europe it still can be considered a novel soil management practice as it is applied on only around 2% of the annual cropland. A paradigm shift and innovative approaches are needed both to recognise the principles of Conservation Agriculture as the only cost-effective, and thus overall sustainable soil management practices capable to deliver the soil-mediated ecosystem services and to make Conservation Agriculture systems work and accepted as the best compromise to attain better soil quality

Teor de açúcar da água residuária do processamento do café.

A fermentação dos açúcares contidos na mucilagem da água residuária do café (ARC) possibilita obter álcool. Para se obter bom rendimento de álcool é necessário ajustar o teor de açúcar da ARC para 16° Brix. O trabalho teve como objetivo quantificar os teores de açúcar da ARC, após sucessivas reciclagens no processo de desmucilamento. Colocou-se água de torneira em amostras de café cereja descascado, das variedades Bourbon Vermelho e Bourbon Amarelo, e a mucilagem foi extraída, girando-se um bastão de vidro, por 3 minutos. Foram feitas até seis extrações, em seqüência, reciclando-se a ARC obtida. Os teores de açúcar da ARC aumentaram linearmente com o aumento do número de extrações realizadas. O teor de açúcar da ARC elevou-se de 3,1 para 9,3° Brix, após cinco extrações, e de 2,6 para 10,3° Brix, após seis extrações da mucilagem do cereja descascado, das variedades Bourbon Vermelho e Bourbon Amarelo, respectivamente

Group theory for structural analysis and lattice vibrations in phosphorene systems

Group theory analysis for two-dimensional elemental systems related to phosphorene is presented, including (i) graphene, silicene, germanene and stanene, (ii) dependence on the number of layers and (iii) two stacking arrangements. Departing from the most symmetric $D_{6h}^{1}$ graphene space group, the structures are found to have a group-subgroup relation, and analysis of the irreducible representations of their lattice vibrations makes it possible to distinguish between the different allotropes. The analysis can be used to study the effect of strain, to understand structural phase transitions, to characterize the number of layers, crystallographic orientation and nonlinear phenomena.Comment: 24 pages, 3 figure

NIR Luminosity Function of Galaxies in Close Major-Merger Pairs and Mass Dependence of Merger Rate

A sample of close major-merger pairs (projected separation ${\rm 5 \leq r \leq 20 h^{-1}}$ kpc, ${\rm K_s}$ band magnitude difference $\delta {\rm K_s} \leq 1$ mag) is selected from the matched 2MASS-2dFGRS catalog of Cole et al. (2001). The pair primaries are brighter than ${\rm K_s} = 12.5$ mag. After corrections for various biases, the comparison between counts in the paired galaxy sample and counts in the parent sample shows that for the local `M* galaxies' sampled by flux limited surveys, the fraction of galaxies in the close major-merger pairs is 1.70$\pm 0.32$. Using 38 paired galaxies in the sample, a ${\rm K_s}$ band luminosity function (LF) is calculated. This is the first unbiased LF for a sample of objectively defined interacting/merging galaxies in the local universe, while all previously determined LFs of paired galaxies are biased by mistreating paired galaxies as singles. A stellar mass function (MF) is translated from the LF. Compared to the LF/MF of 2MASS galaxies, a differential pair fraction function is derived. The results suggest a trend in the sense that less massive galaxies may have lower chance to be involved in close major-merger pairs than more massive galaxies. The algorithm presented in this paper can be easily applied to much larger samples of 2MASS galaxies with redshifts in near future.Comment: Accepted by ApJL, 16 pages, 2 figure

Avaliação de tolerância à seca em progênies híbridas de citros.

O Brasil destaca-se como maior produtor mundial de citros e maior produtor e exportador de suco concentrado congelado de laranja, sendo a Bahia o segundo maior produtor de laranja do país, superada apenas por São Paulo. Apesar da sua importância, a vulnerabilidade da citricultura nordestina, a exemplo da brasileira, é grande, pela presença quase única da combinação laranjeira 'Pera' [Citrus sinensis (L.) Osbeck] / limoeiro 'Cravo' (C. limonia Osbeck) na sustentação dos pomares, tornando urgente um programa de diversificação de variedades. A citricultura baiana está concentrada na Grande Unidade de Paisagem de Tabuleiros Costeiros, onde são registradas precipitações pluviais anuais de 1.000 mm a 1.200 mm, distribuídas em 8 a 10 meses, com dois a seis meses de deficiência hídrica, sendo o uso de irrigação praticamente nulo. Assim, é desejável o emprego de combinações copa / porta-enxerto que, entre outras características de interesse agronômico, sejam tolerantes à seca. Este trabalho teve como objetivo a identificação, dentro de progênies obtidas a partir de cruzamentos controlados, de seedlings (pés-francos) híbridos com potencial para tolerância à seca.PDF. 061