Fitting isochrones to open cluster photometric data III. Estimating metallicities from UBV photometry

The metallicity is a critical parameter that affects the correct determination fundamental characteristics stellar cluster and has important implications in Galactic and Stellar evolution research. Fewer than 10 % of the 2174 currently catalog open clusters have their metallicity determined in the literature. In this work we present a method for estimating the metallicity of open clusters via non-subjective isochrone fitting using the cross-entropy global optimization algorithm applied to UBV photometric data. The free parameters distance, reddening, age, and metallicity simultaneously determined by the fitting method. The fitting procedure uses weights for the observational data based on the estimation of membership likelihood for each star, which considers the observational magnitude limit, the density profile of stars as a function of radius from the center of the cluster, and the density of stars in multi-dimensional magnitude space. We present results of [Fe/H] for nine well-studied open clusters based on 15 distinct UBV data sets. The [Fe/H] values obtained in the ten cases for which spectroscopic determinations were available in the literature agree, indicating that our method provides a good alternative to determining [Fe/H] by using an objective isochrone fitting. Our results show that the typical precision is about 0.1 dex

Complex Network Tools to Understand the Behavior of Criminality in Urban Areas

Complex networks are nowadays employed in several applications. Modeling urban street networks is one of them, and in particular to analyze criminal aspects of a city. Several research groups have focused on such application, but until now, there is a lack of a well-defined methodology for employing complex networks in a whole crime analysis process, i.e. from data preparation to a deep analysis of criminal communities. Furthermore, the "toolset" available for those works is not complete enough, also lacking techniques to maintain up-to-date, complete crime datasets and proper assessment measures. In this sense, we propose a threefold methodology for employing complex networks in the detection of highly criminal areas within a city. Our methodology comprises three tasks: (i) Mapping of Urban Crimes; (ii) Criminal Community Identification; and (iii) Crime Analysis. Moreover, it provides a proper set of assessment measures for analyzing intrinsic criminality of communities, especially when considering different crime types. We show our methodology by applying it to a real crime dataset from the city of San Francisco - CA, USA. The results confirm its effectiveness to identify and analyze high criminality areas within a city. Hence, our contributions provide a basis for further developments on complex networks applied to crime analysis.Comment: 7 pages, 2 figures, 14th International Conference on Information Technology : New Generation

Cork derived TiO2 biomorphic ecoceramics

Environmentally conscious biomorphic ceramics (Ecoceramics) are a new class of material manufactured from renewable resources and wastes. Sustainable cork wastes were pyrolysed, and this activated carbon template infiltrated with a sol-gel precursor (from aqueous green-chemistry) to form TiO2 on heating in air, with the honeycomb microstructure of cork. Physical and optical band gap properties were characterised by XRD, SEM and Raman and UV–vis spectroscopy, and differences between alkaline and acidic activation of the carbon template also studied. With activation by HCl, HNO3 or H2SO4, a mixture of anatase and rutile formed. NaOH activation resulted in pure anatase, but a large amount of Na was retained. At 1000 °C acid activated ecoceramics formed pure rutile, but the NaOH activated one formed Na2Ti6O13 (sodium hexatitanate) as the major phase, coexisting with anatase, brookite and rutile. This material is worth further investigation, as Na2Ti6O13 is reported as a photocatalyst in its own right

Accuracy of genomic prediction for tick resistance in Braford and Hereford cattle.

This work aimed to determine the accuracy and bias of genomic predictions of Braford (BO) and Hereford (HH) cattle genetic resistance to ticks