Institution
Instituto Politécnico Nacional
Education•Mexico City, Mexico•
About: Instituto Politécnico Nacional is a education organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Population & Control theory. The organization has 43351 authors who have published 63315 publications receiving 938532 citations. The organization is also known as: Instituto Politécnico Nacional & Instituto Politecnico Nacional.
Topics: Population, Control theory, Thin film, Catalysis, Nonlinear system
Papers published on a yearly basis
Papers
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TL;DR: In this article, an isotropic damage model for concrete is presented, where the main features of the model are: limited number of constitutive parameters required; independent modelling of tension and compression behaviour by means of two damage variables and two separate activation criteria (bi-dissipative model); independent definition of tension/compression fracture energies; consistent modelling of the unilateral effect upon transition from tension to compression; and the effectiveness of fracture energy based regularization strategy.
224 citations
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TL;DR: In this article, a description of morphological changes of particles along spray drying was carried out by means of scanning electron and light microscopy, where samples of atomized material (40% maltodextrin solution) were withdrawn during drying from a laboratory spray drier at various vertical distances from the atomizing nozzle.
223 citations
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TL;DR: It was found that zero tillage most affected the bacterial communities, while crop residue management affected the microbial communities more than when conventional tillage was applied, indicating that even though phylotypes changed, the number and diversity of theacterial communities were similar.
Abstract: In this study, the effect of limited tillage versus traditional tillage, residue retention versus removal and crop rotation (maize–wheat) versus monoculture (maize) on the bacterial community structure in soils was investigated by means of 454 pyrosequencing of the 16S rRNA gene. Using taxonomic and phylogenetic information it was found that zero tillage most affected the bacterial communities. The relative abundance of Actinobacteria, Betapreoteobacteria and Gammaproteobacteria was affected by tillage and correlated to the total organic carbon (TOC) and clay content in soil. Residue management had a significant effect on the bacterial community structure when phylogenetic membership and the total enumeration of bacteria were considered. Residue management affected the relative abundance of Bacteroidetes, Betaproteobacteria, Cyanobacteria and Gemmatimonadetes. When no tillage was applied, crop residue management affected the microbial communities more than when conventional tillage was applied. Wheat–maize rotation or crop monoculture did not affect the bacterial community structure. No significant differences in richness, diversity and total abundance of bacteria was found between the treatments. This indicated that even though phylotypes changed, the number and diversity of the bacterial communities were similar.
223 citations
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Agenzia Spaziale Italiana1, INAF2, Aalto University3, Helsinki Institute of Physics4, Goddard Space Flight Center5, International School for Advanced Studies6, Spanish National Research Council7, Istituto Nazionale di Fisica Nucleare8, Instituto Politécnico Nacional9, University of Perugia10, University of Geneva11, University of Michigan12, Max Planck Society13, University of Padua14, University of Turku15, University of Manchester16, Australia Telescope National Facility17, Pennsylvania State University18, University of Milan19, SLAC National Accelerator Laboratory20, University of Helsinki21, California Institute of Technology22, University of Cambridge23, Russian Academy of Sciences24, University of Ferrara25, Haverford College26, Tufts University27, University of Oviedo28, Chinese Academy of Sciences29
TL;DR: In this paper, simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard Xray, and gamma-ray bands, with additional 5 GHz flux-density limits to ensure a good probability of a Planck detection.
Abstract: We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and gamma-ray bands, with additional 5 GHz flux-density limits to ensure a good probability of a Planck detection. We compare our results to those of a companion paper presenting simultaneous Planck and multi-frequency observations of 104 radio-loud northern active galactic nuclei selected at radio frequencies. While we confirm several previous results, our unique data set allows us to demonstrate that the selection method strongly influences the results, producing biases that cannot be ignored. Almost all the BL Lac objects have been detected by the Fermi Large Area Telescope (LAT), whereas 30% to 40% of the flat-spectrum radio quasars (FSRQs) in the radio, soft X-ray, and hard X-ray selected samples are still below the gamma-ray detection limit even after integrating 27 months of Fermi-LAT data. The radio to sub-millimetre spectral slope of blazars is quite flat, with (alpha) approx 0 up to about 70GHz, above which it steepens to (alpha) approx -0.65. The BL Lacs have significantly flatter spectra than FSRQs at higher frequencies. The distribution of the rest-frame synchrotron peak frequency (nu(sup s)(sub peak)) in the spectral energy distribution (SED) of FSRQs is the same in all the blazar samples with (nu(sup s)(sub peak)) = 10(exp 13.1 +/- 0.1) Hz, while the mean inverse Compton peak frequency, (nu(sup IC)(sub peak)), ranges from 10(exp 21) to 10(exp 22) Hz. The distributions of nu(sup s)(sub peak) and nu(sup IC)(sub peak) of BL Lacs are much broader and are shifted to higher energies than those of FSRQs; their shapes strongly depend on the selection method. The Compton dominance of blazars. defined as the ratio of the inverse Compton to synchrotron peak luminosities, ranges from less than 0.2 to nearly 100, with only FSRQs reaching values larger than about 3. Its distribution is broad and depends strongly on the selection method, with gamma-ray selected blazars peaking at approx 7 or more, and radio-selected blazars at values close to 1, thus implying that the common assumption that the blazar power budget is largely dominated by high-energy emission is a selection effect. A comparison of our multi-frequency data with theoretical predictions shows that simple homogeneous SSC models cannot explain the simultaneous SEDs of most of the gamma-ray detected blazars in all samples. The SED of the blazars that were not detected by Fermi~LAT may instead be consistent with SSC emission. Our data challenge the correlation between bolometric luminosity and nu(sup s)(sub peak) predicted by the blazar sequence.
222 citations
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European Southern Observatory1, Uppsala University2, Max Planck Society3, INAF4, Université libre de Bruxelles5, Instituto Politécnico Nacional6, Lund University7, University of Concepción8, Pontifical Catholic University of Chile9, Heidelberg University10, Millennium Institute11, University of Porto12, Complutense University of Madrid13, Vilnius University14, Leibniz Institute for Astrophysics Potsdam15, University of Cambridge16, University of La Laguna17, Spanish National Research Council18, Centre national de la recherche scientifique19, Paris Diderot University20, University of Padua21, University of Bologna22, Indiana University23, Massachusetts Institute of Technology24, University of Catania25, University of Liège26, University of Florence27, Australian National University28, University of Hertfordshire29, University of Edinburgh30, Keele University31, University of Alicante32, European Space Research and Technology Centre33, Royal Observatory of Belgium34, Valparaiso University35
TL;DR: In this article, the Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 10(5) stars and high-resolution UVES spectra of about 5000 stars.
Abstract: Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 10(5) stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already observed 1447 FGK-type stars. Aims. These UVES spectra are analyzed in parallel by several state-of-the-art methodologies. Our aim is to present how these analyses were implemented, to discuss their results, and to describe how a final recommended parameter scale is defined. We also discuss the precision (method-to-method dispersion) and accuracy (biases with respect to the reference values) of the final parameters. These results are part of the Gaia-ESO second internal release and will be part of its first public release of advanced data products. Methods. The final parameter scale is tied to the scale defined by the Gaia benchmark stars, a set of stars with fundamental atmospheric parameters. In addition, a set of open and globular clusters is used to evaluate the physical soundness of the results. Each of the implemented methodologies is judged against the benchmark stars to define weights in three different regions of the parameter space. The final recommended results are the weighted medians of those from the individual methods. Results. The recommended results successfully reproduce the atmospheric parameters of the benchmark stars and the expected T-eff-log g relation of the calibrating clusters. Atmospheric parameters and abundances have been determined for 1301 FGK-type stars observed with UVES. The median of the method-to-method dispersion of the atmospheric parameters is 55K for T-eff, 0.13dex for log g and 0.07 dex for [Fe/H]. Systematic biases are estimated to be between 50-100 K for T-eff, 0.10-0.25 dex for log g and 0.05-0.10 dex for [Fe/H]. Abundances for 24 elements were derived: C, N, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, Nd, and Eu. The typical method-to-method dispersion of the abundances varies between 0.10 and 0.20 dex. Conclusions. The Gaia-ESO sample of high-resolution spectra of FGK-type stars will be among the largest of its kind analyzed in a homogeneous way. The extensive list of elemental abundances derived in these stars will enable significant advances in the areas of stellar evolution and Milky Way formation and evolution.
222 citations
Authors
Showing all 43548 results
Name | H-index | Papers | Citations |
---|---|---|---|
Giacomo Bruno | 158 | 1687 | 124368 |
Giuseppe Mancia | 145 | 1369 | 139692 |
Giorgio Maggi | 135 | 1323 | 90270 |
Salvatore Nuzzo | 133 | 1533 | 91600 |
Giuseppe Iaselli | 133 | 1514 | 91558 |
Marcello Abbrescia | 132 | 1400 | 84486 |
Louis Antonelli | 132 | 1089 | 83916 |
Donato Creanza | 132 | 1452 | 89206 |
Alexis Pompili | 131 | 1437 | 86312 |
Gabriella Pugliese | 131 | 1309 | 88714 |
Giovanna Selvaggi | 131 | 1159 | 83274 |
Heriberto Castilla-Valdez | 130 | 1659 | 93912 |
Ricardo Lopez-Fernandez | 129 | 1213 | 81575 |
Cesare Calabria | 128 | 1095 | 76784 |
Paolo Vitulo | 128 | 1120 | 79498 |