Multichromatic colour-magnitude diagrams of the globular cluster NGC 6366

We present multichromatic isochrone fits to the colour-magnitude data of the globular cluster NGC 6366, based on Hubble Space Telescope Advanced Camera for Surveys/Wide Field Channel and Southern Astrophysical Research photometric data. We corrected the photometric data for differential reddening and calculated the mean ridge line of the colour-magnitude diagrams. We compared the isochrones of Dartmouth Stellar Evolution Database and PAdova and TRieste Stellar Evolution Code both with microscopic diffusion starting on the main sequence. Bracketing all previous determinations of this cluster, we tested metallicities from [Fe/H]=-1.00 to [Fe/H]=-0.50, and ages from 9 to 13 Gyr. After determining the total to selective extinction ratio only from stars belonging to this cluster, R_V=3.06+/-0.14, we found the parameters for this cluster to be E(B-V)=0.69+/-0.02(int)+/-0.04(ext), (m-M)_V=15.02+/-0.07(int)+/-0.13(ext), Age=11+/-1.15 Gyr. Evolutionary models fail to reproduce the low-Teff sequence in multiband colour-magnitude diagrams, indicating that they still have an incomplete physics. We found that the Dartmouth Stellar Evolution Database isochrones better fit the subgiant branch and low main sequence than the PAdova and TRieste Stellar Evolution Code.Comment: 9 pages, 5 figure

GIS and Remote Sensing to Support Precision Viticulture for Analysis of Vineyards in the Campanha Wine Region, Brazil

Agricultural products depend upon the geographical area of production and their quality depends on environment and crop management. Grapevine cultivars can be adapted to the environment, resulting in differences in fruit quality, which will produce different wines. The knowledge of the territory gives value to agricultural products and the use of free software has advantages to associate spatial data with Geographical Information System (GIS) functions for Digital Image Processing (DIP), spatial analysis, Digital Elevation Models (DEM) and databases. The objective of this study was analyze spatially vineyards of Vitis vinifera in south Brazil, using DEM for zoning landscape and employing RapidEye images at different crop stages, in order to follow the Normalized Difference Vegetation Index (NDVI) and test tools that allow the producer a customized management between vineyards and within each vineyard. The software gvSIG was used to evaluate NDVI for plant vigor in order to infer diseases, water status, and other factors. NDVI, altitude, slope, and exposure average were generated for 64 vineyards. To a Cabernet Sauvignon area, a map was generated, showing the variability of the vineyard by resampling of pixel size image, from five to one-meter spatial resolution and zoning according to critical variables for the vineyard. In conclusion, geotechnology is important for viticulture, as a support to environmental diagnostics and are a strategic application for agricultural management. Analytical tools and sensors can provide fast, easily accessible data to all users, being a technology prone to be of widespread access for the end user

Aplicação de processamento digital de imagens orbitais e SIG para apoio à agricultura de precisão nas culturas da videira e macieira no Rio Grande do Sul.

O estudo por sensoriamento remoto e SIG para as culturas de videira e macieira no Brasil requereu a busca por imagens de satélite adequadas à aplicação de índice de vegetação por diferença normalizada (NDVI). Dados ALOS (Advanced Land Observing Satellite) foram testados em duas áreas experimentais no Estado do Rio Grande do Sul. Os resultados apontam que a diferenciação de índices no âmbito inter e intra parcelas podem auxiliar no manejo da cultura

Identidade espectral entre cultivares de uvas viníferas em duas regiões da Campanha Gaúcha.

O uso de tecnologias de sensoriamento remoto na análise e na caracterização de assinaturas espectrais de culturas vitícolas por meio de imagens de satélite contribuem para o controle e monitoramento nas tomadas de decisões relativas à gestão da produção e qualidade dos vinhos. O presente trabalho visou separar as assinaturas espectrais de cultivares de uvas viníferas em duas regiões distintas, nos municípios de Santana do Livramento e Candiota, localizados na Campanha Gaúcha. Foram utilizados mapas georreferenciados fornecidos pelos proprietários das áreas com a localização das cultivares para delimitar as regiões de interesse a partir do produto L1B do sensor ASTER (Advanced Spaceborne Thermal and Reflection Radiometer) e coletar as informações de refletância normalizada nas faixas espectrais das bandas do VNIR (Visible Near Infrared) e SWIR (Short Wave Infrared) de 48 parcelas das cultivares Vitis vinífera Cabernet Sauvignon, Merlot, Chardonnay, Pinot Noir, Sauvignon Blanc e Tannat. As classes de estudo compreenderam as cultivares e para teste de desempenho foi incluída a classe ?banhado? nas duas regiões. As imagens foram submetidas às correções do efeito Cross Talk, reamostragem para 15 metros das bandas do SWIR e correção atmosférica utilizando o algoritmo FLAASH (Fast Line-of-Sight Atmospheric Analysis of Spectral Hypercubes). Para verificar a separabilidade das variedades foi utilizado o algoritmo de classificação Máxima Verossimilhança e também a Análise Discriminante das médias de refletância de cada parcela nas bandas (1, 2, 3N, 4, 5, 6, 7, 8 e 9). Os resultados obtidos mostraram que a Análise Discriminante (AD) distinguiu totalmente as regiões, enquanto a separabilidade das assinaturas espectrais das cultivares teve menor desempenho, com percentagens entre 37 e 75% de acurácia. O classificador de Máxima Verossimilhança, aplicado separadamente a cada região, teve desempenho de 91% de acurácia para a região de Santana do Livramento e 75% para Candiota. Os resultados indicam que dados de refletância obtidos de imagens ASTER permitem com relativo sucesso a discriminação espectral de classes de vegetação com assinaturas espectrais muito próximas entre si, como é o caso de cultivares vitícolas. A distinta separação das regiões, caracterizadas como ?terroirs? vitícolas, pode ser atribuída às diferenças físico-químicas do solo das regiões transmitidas à folhagem das videiras e em seguida às suas refletâncias. A classe ?banhado? teve assinatura espectral totalmente diferente das cultivares e, portanto, foi identificada e totalmente separada das classes como era esperado

Geologia: um critério do meio físico para estabelecimento de indicações geográficas de vinhos finos na Serra Gaúcha, RS, Brasil.

O desenvolvimento da vitivinicultura no Brasil tem sido associado a pesquisas lideradas pela Embrapa Uva e Vinho e seus parceiros, a fim de desenvolver indicações geográficas (IG), a primeira delas sendo Vale dos Vinhedos. Este ativo de propriedade intelectual segue requisitos legais e técnicos, incluindo identidade geográfica.Resumo

Metastable crystalline AuGe catalysts formed during isothermal germanium nanowire growth.

We observe the formation of metastable AuGe phases without quenching, during strictly isothermal nucleation and growth of Ge nanowires, using video-rate lattice-resolved environmental transmission electron microscopy. We explain the unexpected formation of these phases through a novel pathway involving changes in composition rather than temperature. The metastable catalyst has important implications for nanowire growth, and more broadly, the isothermal process provides both a new approach to growing and studying metastable phases, and a new perspective on their formation.A. D. G. acknowledges funding from the Marshall Aid Commemoration Commission and the National Science Foundation. S. H. and C. D. acknowledge funding from the Royal Society. S. H. acknowledges funding from ERC grant InsituNANO (n°279342).This is the accepted manuscript. The final version is available from APS at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.255702

Implantação da biblioteca espectral de rochas e solos da CPRM: um resgate da memória espectral da litoteca e apoio a projetos Projetos de Levantamentos Geológicos Básicos (PLGB).

Establisment of a rocks and soils spectral library is proposed for CPRM-Brazilian Geological Survey, for improvement of rocks and soils spectral signature obtainance as a help for field data and satellite images correlation for geological mapping purposes. Spectrometric measures will be runned on grinded rocks by means of a Portable Spectrometer for Analytical Mineral Identification (POSAM), witch operates in the infrared spectra band at CPRM?s Remote Sensing and Spectroradiometry Lab. Hydrothermal alteration studies employng spectroradiometry and ASTER data DIP have been done for shiel rocks on southern Brazil, and are presented for 3 areas. At Lavras do Sul Minig District, gold and cooper prospects hosted in neoproterozoic volcanics and post tectonic granithoids had deposits and host rocks identified, plus hydrothermal alteration assemblages as white mica, montmorillonite, kaolinita. epidote, zeolite, calcite and jarosite. Vila Palma?s gold cooper and molibdenium propects, hosted by metamorphic mafic volcano-sedimentary sequence neoprotherozoic in age, showed as early results hidrothermal alteration assemblages like kaolinite,chlorite, muscovite, calcite and zeolite group minerals on sulphide bearing quarts veins, besides anphibole and chlorite on host rocks and zeolite+chlorite or chlorite+calcite+zeolite on the ores. At Pinheiro Machado, neoprotherozoic granite-gnaissic complexe and intrusive granitic assemblage followed by gabbroid rocks has been investigated for establishment of vine terroir. Alteration mineral assemblages like montmorilinite, sericite, clorite, natrolite; laumontite, calcite and epidote seem to discriminate distinct litostratigraphic units. Concluding, the establishment of a spectral library on CPRM will improve the data bank of Brazilian Geologic Survey, already in GIS environment, helping geological mapping and prospective activities

Comparação de dados de modelo digital de elevação - MDE: ASTER e SRTM por processamento digital de imagem para identificação de terroir vitivinícola na Folha Encruzilhada do Sul, RS, Brasil.

In the ?Metade Sul? region, Rio Grande do Sul, Brazil, some vineyard appeared and studies approaching geographic indication using geotechnology have been developed by Embrapa Grape and Wine, such as Serra Gaúcha and others places. The object of this work is to test digital elevation models (MDE) from ASTER and SRTM data, with different resolutions, to generate elements to characterize the natural factors in Serra do Sudeste, Encruzilhada do Sul, situated in the center of Rio Grande do Sul State, Brazil. This work supports studies of winery terroir, that relates to natural characteristics of farm, such as soil, rock, landscape and climate, that determine specificity to wines produced to each place. Orbital images have been used to identify terroirs to generate landscape models, by digital image processing (DIP) and integrate thematic maps to generate terroir potential units. For the moment, this study approaches terroir from landscape and its data and their products were crossed into geographic information system (GIS) environment from low (SRTM) and medium resolution (ASTER) to supports choice of orbital source for agricultural zoning, in order to establish potential criteria to identify terroirs in this region. The MDEs generated elevation, declivity and aspect maps, also derived data to applied in wine management and after, were integrated and reclassified. The analysis of all information in the SIG led to compare different orbital data with different resolution and how much these attributes (altimetry, declivity and aspect) can support grape vine development

Color Evaporation and Elastic Υ\Upsilon Photoproduction at DESY HERA

The diffractive photoproduction of vector mesons is usually described considering the two-gluon (Pomeron) exchange, non-diagonal parton distributions and the contribution of the real part to the cross section. In this letter we analyze the diffractive photoproduction of the $\Upsilon$ at HERA using an alternative model, the Color Evaporation Model (CEM), where the cross section is simply determined by the boson-gluon cross section and an assumption for the production of the colorless state. We verify that, similarly to the $J/\Psi$ case, the HERA data for this process can be well described by the CEM. Moreover, we propose the analyzes of the ratio $R = \sigma_{\Upsilon} / \sigma_{J/\Psi}$ to discriminate between the distinct approaches.Comment: 7 pages, 3 figures, accepted for publication in PRD (Brief Reports

Meson Form Factors and Non-Perturbative Gluon Propagators

The meson (pion and kaon) form factor is calculated in the perturbative framework with alternative forms for the running coupling constant and the gluon propagator in the infrared kinematic region. These modified forms are employed to test the sensibility of the meson form factor to the nonperturbative contributions. Its is a powerful discriminating quantity and the results obtained with a particular choice of modified running coupling constant and gluon propagator have a good agreement with the available data, for both mesons, indicating the robustness of the method of calculation. Nevertheless, nonperturbative aspects may be included in the perturbative framework of calculation of exclusive processes.Comment: 18 pages, 7 figures. Discutions added, clarifing figures. Accepted to be published in Phys. Rev.