Science and Business

There are two kinds of scientists in evolutionary studies that need a space of debate:  the specialists in evolutionary studies in business and all other evolutionary scientists in general. The themes of the discussion are the behaviour, growth, reproduction, and organizational structures of the firm

The white dwarf cooling sequence of 47 Tucanae

47 Tucanae is one of the most interesting and well observed and theoretically studied globular clusters. This allows us to study the reliability of our understanding of white dwarf cooling sequences, to confront different methods to determine its age, and to assess other important characteristics, like its star formation history. Here we present a population synthesis study of the cooling sequence of the globular cluster 47 Tucanae. In particular, we study the distribution of effective temperatures, the shape of the color-magnitude diagram, and the corresponding magnitude and color distributions. We do so using an up-to-date population synthesis code based on Monte Carlo techniques, that incorporates the most recent and reliable cooling sequences and an accurate modeling of the observational biases. We find a good agreement between our theoretical models and the observed data. Thus, our study, rules out previous claims that there are still missing physics in the white dwarf cooling models at moderately high effective temperatures. We also derive the age of the cluster using the termination of the cooling sequence, obtaining a good agreement with the age determinations using the main-sequence turn-off. Finally, we find that the star formation history of the cluster is compatible with that btained using main sequence stars, which predict the existence of two distinct populations. We conclude that a correct modeling of the white dwarf population of globular clusters, used in combination with the number counts of main sequence stars provides an unique tool to model the properties of globular clusters.Comment: 6 pages and 4 figures accepted for publication in A &

Monte Carlo simulation of a liquid scintillation counter using geant4 code

This paper presents a first approach to the use of the GEANT4 Monte Carlo (MC) technique in liquid scintil-lation counting (LSC) applied to measurements in radiological laboratories. The GEANT4 software was developed by RD44,a worldwide collaboration of national institutes, laboratories, and large high-energy physics experiments. GEANT4 is a pub-lic software package composed of tools that can be used to accurately simulate the passage of particles through matter. TheGEANT4 catalog of processes at optical wavelengths includes refraction and reflection at medium boundaries, bulk absorp-tion, and Rayleigh scattering. Processes that produce optical photons include the Cherenkov effect, transition radiation, andscintillation.The simulated setup includes a vial containing the scintillation cocktail in between 2 opposite photomultipliers tubes (PMTs)working in sum-coincidence mode. The decay of several beta emitters (such as 14C and 3H) can be simulated, as well as alphaor EC emitters. Additionally, significant information could be obtained, such as the energy deposited by decay into the scin-tillation cocktail or the light output generated into the scintillation cocktail. GEANT4 is a useful tool for efficiency calibra-tion, stopping power calculations, or wall effect studies for different scintillation cocktails and geometries.Junta de Andalucia Excellence Project RNM-0256

New lanthanide phosphonates structures obtained using XRPD data

5 páginas, 2 figuras, 3 tablas.-- Trabajo presentado como póster a la 12th European Powder Diffraction Conference (EPDIC 2010).-- et al.Seven lanthanide diphosphonates, [H3N(CH2)4NH3]Ln[hedpH][hedpH2] (Ln = La, Pr, Sm, Eu, Gd, Tb, Er; hedp = 1 hydroxyethylidenediphosphonate) have been synthesized with 1,4-diaminobutane as the template. The structures were obtained starting from the known X-ray single crystal model of lanthanum compound, with the X-ray powder diffraction data for these seven compounds. H-atoms were introduced using geometrical considerations. Rietveld fits of the experimental diffractograms confirm the isostructurality of all compounds in the series, and show the different behaviour between the two distances M-M existing in the structures.Financial support from Spanish MICINN (MAT2006-01997, MAT2010-15095 and ‘Factoría de Cristalización’ Consolider Ingenio 2010), Un-iversidad de Oviedo and Banco Santander is acknowledged. FEDER support is also acknowledged.Peer reviewe

Crystal structure of (E)-1-{[(3,5-dimethylphenyl)imino]methyl}naphthalen-2-ol

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence.The title compound, C19H17NO, has an E conformation about the N=C bond. The mol­ecule is relatively planar, with the benzene ring and naphthalene ring plane being inclined to one another by 4.28 (10)°. There is an intra­molecular O—H⋯N hydrogen bond generating an S(6) ring motif. In the crystal, mol­ecules are linked via C—H⋯O hydrogen bonds, forming chains propagating along [100]. Within the chains there are π–π inter­actions involving the benzene ring and the naphthalene ring system of an adjacent mol­ecule [inter-centroid distance = 3.6405 (14) Å].We thank the Spanish Ministerio de Economía y Competitividad (MAT2013-40950-R and FPI grants: BES-2011-046948 to author MSMA) and the ERDF for financial support.Peer Reviewe

Dark energy survey year 3 results: weak lensing shape catalogue

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMWe present and characterize the galaxy shape catalogue from the first 3 yr of Dark Energy Survey (DES) observations, over an effective area of 4143 deg2 of the southern sky. We describe our data analysis process and our self-calibrating shear measurement pipeline metacalibration, which builds and improves upon the pipeline used in the DES Year 1 analysis in several aspects. The DES Year 3 weak-lensing shape catalogue consists of 100 204 026 galaxies, measured in the riz bands, resulting in a weighted source number density of neff = 5.59 gal arcmin-2 and corresponding shape noise σe = 0.261. We perform a battery of internal null tests on the catalogue, including tests on systematics related to the point spread function (PSF) modelling, spurious catalogue B-mode signals, catalogue contamination, and galaxy propertie