359 research outputs found

    Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: The KINGFISH Sample

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    Interstellar dust and starlight are modeled for the galaxies of the project “Key Insights on Nearby Galaxies: A FarInfrared Survey with Herschel.” The galaxies were observed by the Infrared Array Camera and the Multiband Imaging Photometer for Spitzer on Spitzer Space Telescope, and the Photodetector Array Camera and Spectrometer and the Spectral and Photometric Imaging Receiver on Herschel Space Observatory. With data from 3.6 to 500 μm, dust models are strongly constrained. Using a physical dust model, for each pixel in each galaxy we estimate (1) dust surface density, (2) dust mass fraction in polycyclic aromatic hydrocarbons (PAHs), (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in subregions with high starlight intensity. The dust models successfully reproduce the observed global and resolved spectral energy distributions. With the angular resolution of Herschel, we obtain well-resolved maps (available online) for the dust properties. As in previous studies, we find the PAH fraction qPAH to be an increasing function of metallicity, with a threshold oxygen abundance Z/Ze ≈ 0.1, but we find the data to be fitted best with qPAH increasing linearly with log O H ( ) above a threshold value of 0.15(O/H)e. We obtain total dust masses for each galaxy by summing the dust mass over the individual map pixels; these “resolved” dust masses are consistent with the masses inferred from a model fit to the global photometry. The global dust-to-gas ratios obtained from this study are found to correlate with galaxy metallicities. Systems with Z/Ze 0.5 have most of their refractory elements locked up in dust, whereas in systems with Z/Ze 0.3 most of these elements tend to remain in the gas phase. Within galaxies, we find that qPAH is suppressed in regions with unusually warm dust with nL L n ( ) 70 m 0.4 m dust. With knowledge of one long-wavelength flux density ratio (e.g., f160/f500), the minimum starlight intensity heating the dust (Umin) can be estimated to within ∼50%, despite a variation in Umin of more than two orders of magnitude. For the adopted dust model, dust masses can be estimated to within ∼0.2 dex accuracy using the f160/f500 flux ratio and the integrated dust luminosity, and to ∼0.07 dex accuracy using the 500 μm luminosity nLn ( ) 500 mm alone. There are additional systematic errors arising from the choice of dust model, but these are hard to estimate. These calibrated prescriptions for estimating starlight heating intensity and dust mass may be useful for studies of high-redshift galaxies

    Changes in period and cohort effects on haematological cancer mortality in Spain, 1952-2006

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    BACKGROUND: In contrast to other haematological cancers, mortality from non-Hodgkin's lymphoma and multiple myeloma increased dramatically during the second half of the 20th century in most developed countries. This widespread upward trend remains controversial, as it may be attributable either to progressive improvements in diagnosis and certification or to increasing exposures to little-known but relevant risk factors. METHODS: To assess the relative contribution of these factors, we analysed the independent effects of age, death period, and birth cohort on haematological cancer mortality rates in Spain across the period 1952-2006. Weighted joinpoint regression analyses were performed to detect and estimate changes in period and cohort curvatures. RESULTS: Although mortality rates were consistently higher among men, trends across periods and cohorts were virtually identical in both sexes. There was an early period trend reversal in the 1960s for Hodgkin's disease and leukaemia, which was delayed to the 1980s for multiple myeloma and the 1990s for non-Hodgkin's lymphoma. Birth cohort patterns showed a first downturn for generations born in the 1900s and 1910s for all haematological cancers, and a second trend reversal for more recent cohorts born in the 1950s and 1960s for non-Hodgkin's lymphoma and leukaemia. CONCLUSIONS: The sustained decline in Hodgkin's disease mortality and the levelling off in leukaemia seem to be driven by an early period effect linked to improvements in disease treatment, whereas the steep upward trends in non-Hodgkin's lymphoma and multiple myeloma mortality in Spain are more likely explained by a cohort effect linked to better diagnosis and death certification in the elderly. The consistent male excess mortality across all calendar periods and age groups points to the importance of possible sex-related genetic markers of susceptibility in haematological cancers.The study was supported in part by a research grant from the Spanish Health Research Fund (FIS PI11/00871). The study sponsor had no role in the study design; the collection, analysis, and interpretation of data; the writing of the manuscript; and the decision to submit the manuscript for publication.S

    La Condena de la Libertad: De Túpac Amaru II al Bicentenario Peruano en Seis Ensayos y un Colofón

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    Una vez más, Alberto Vergara nos sorprende con un excelente libro sobre la realidad nacional.1 Esta vez, con su coeditor, Paulo Drinot, Vergara reúne un grupo formidable de historiadores y politólogos para escribir una narrativa de más de 200 años de historia nacional

    Perú: Consolidación Fiscal 1980-2020 y Retos a la Fecha —Una Aproximación

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    Esta nota narra la consolidación fiscal ocurrida en los últimos 40 años, las evoluciones en los conceptos de déficit fiscal monitoreados en el análisis fiscal, y el impacto de la condicionalidad del Fondo Monetario Internacional (FMI) inmersa en los sucesivos programas financieros subscritos entre Perú y el FMI sobre la evolución de los principales agregados fiscales. La nota también elabora en los logros y retos de gestión pública a la fecha

    Grammar and teaching of languages

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    Thermodynamics of Small Magnetic Particles

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    In the present paper, we discuss the interpretation of some of the results of the thermodynamics in the case of very small systems. Most of the usual statistical physics is done for systems with a huge number of elements in what is called the thermodynamic limit, but not all of the approximations done for those conditions can be extended to all properties in the case of objects with less than a thousand elements. The starting point is the Ising model in two dimensions (2D) where an analytic solution exits, which allows validating the numerical techniques used in the present article. From there on, we introduce several variations bearing in mind the small systems such as the nanoscopic or even subnanoscopic particles, which are nowadays produced for several applications. Magnetization is the main property investigated aimed for two singular possible devices. The size of the systems (number of magnetic sites) is decreased so as to appreciate the departure from the results valid in the thermodynamic limit; periodic boundary conditions are eliminated to approach the reality of small particles; 1D, 2D and 3D systems are examined to appreciate the differences established by dimensionality is this small world; upon diluting the lattices, the effect of coordination number (bonding) is also explored; since the 2D Ising model is equivalent to the clock model with q=2 degrees of freedom, we combine previous results with the supplementary degrees of freedom coming from the variation of q up to q=20. Most of the previous results are numeric; however, for the case of a very small system, we obtain the exact partition function to compare with the conclusions coming from our numerical results. Conclusions can be summarized in the following way: the laws of thermodynamics remain the same, but the interpretation of the results, averages and numerical treatments need special care for systems with less than about a thousand constituents, and this might need to be adapted for different properties or devices.Fil: Vogel, Eugenio. Universidad de La Frontera; Chile. Center for the Development of Nanoscience and Nanotechnology; ChileFil: Vargas, Patricio. Center for the Development of Nanoscience and Nanotechnology; Chile. Universidad Técnica Federico Santa María; ChileFil: Saravia, Gonzalo. Universidad de La Frontera; ChileFil: Valdes, Julio. Universidad de La Frontera; ChileFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Centres, Paulo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

    Valuación y etapas de un proyecto edilicio en Nuñez, Argentina

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    El escenario político-económico en la Argentina siempre se ha caracterizado por la constante inestabilidad, cada vez aparecen más restricciones y reglas en cuanto al tipo de cambio e ingreso de divisas. Hoy se puede elegir alternativas al tradicional emprendimiento elegido por los argentinos. La tesis va a tratar sobre el análisis de la industria de la construcción en Capital Federal y va a tomar un departamento tipo, en un determinado barrio, para costearlo y analizar su posible retorno

    Significado e importancia de las etapas descriptiva y proyectual en los proyectos de restauración ambiental: término municipal de Mogarraz (Salamanca)

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    El municipio de Mogarraz (Salamanca), incluido en el Parque Natural de Las Batuecas Sierra de Francia, ha sufrido en los últimos años un intenso proceso emigratorio que ha supuesto un abandono de sus tierras y un envejecimiento poblacional. Al hacerse extensible esta realidad al resto de municipios incluidos dentro de los Espacios Protegidos de Castilla y León, surge el Programa Parques Naturales de Castilla y León (septiembre 2002), dirigido a la conservación y el desarrollo socioeconómico del medio rural. Este proyecto, apoyado en el Programa, pretende mejorar las condiciones de vida de la población de Mogarraz, recuperar la actividad económica y social, y potenciar y conservar los valores ambientales que posee. Para ello, se ha diseñado un esquema metodológico que sirve de guía para la elaboración de este tipo de proyectos de restauración. En él se plantean las etapas lógicas y secuenciales para conseguir los objetivos propuestos. El proyecto incluye: etapa descriptiva, diagnóstico de los problemas ambientales, propuesta de soluciones, y etapa proyectual de las actuaciones prioritarias: restauración del área de descanso del núcleo urbano, y recuperación de un antiguo camino con el fin de convertirlo en senda ecológica. Finaliza con el pliego de condiciones, planos, y presupuesto de las obras

    Spectroelectrochemical study of carbon monoxide and ethanol oxidation on Pt/C, PtSn(3:1)/C and PtSn(1:1)/C catalysts

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    PtSn-based catalysts are one of the most active materials toward that contribute ethanol oxidation reaction (EOR). In order to gain a better understanding of the Sn influence on the carbon monoxide (principal catalyst poison) and ethanol oxidation reactions in acidic media, a systematic spectroelectrochemical study was carried out. With this end, carbon-supported PtSnx (x = 0, 1/3 and 1) materials were synthesized and employed as anodic catalysts for both reactions. In situ Fourier transform infrared spectroscopy (FTIRS) and differential electrochemical mass spectrometry (DEMS) indicate that Sn diminishes the amount of bridge bonded CO (COB) and greatly improves the CO tolerance of Pt-based catalysts. Regarding the effect of Sn loading on the EOR, it enhances the catalytic activity and decreases the onset potential. FTIRS and DEMS analysis indicate that the C-C bond scission occurs at low overpotentials and at the same potential values regardless of the Sn loading, although the amount of C-C bond breaking decreases with the rise of Sn in the catalytic material. Therefore, the elevated catalytic activity toward the EOR at PtSn-based electrodes is mainly associated with the improved CO tolerance and the incomplete oxidation of ethanol to form acetic acid and acetaldehyde species, causing the formation of a higher amount of both C2 products with the rise of Sn loading.This research was funded by Fundación Cajacanarias (project BIOGRAF) the Spanish Ministry of Economy and Competitiveness (MINECO) under projects CTQ2011-28913-C02 and ENE2014-52158-C02 (co-funded by FEDER). R.R. acknowledges the FPI program (MINECO) for financial support. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI

    A constraint-free flight simulator package for airborne wind energy systems

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    Proceeding of: 7th International Conference "The Science of Making Torque from Wind" (TORQUE 2018), Milano, 20-22 June, 2018.The LAgrangian Kite SimulAtor (LAKSA) is a freely available software for the dynamic analysis of tethered flying vehicles, such as kites and fixed-wing drones, applied to airborne wind energy generation. This software comprises four simulators. The one, two and four-line simulators, which consider flexible but inelastic tethers, are based on minimal coordinate Lagragian formulations and can be used for the analysis of fly and ground generation systems, kite-based traction systems, and kitesurfing applications, respectively. The configuration of the mechanical system in the fourth simulator can be defined by the user, who can select the number of flying vehicles and the properties of the elastic and flexible tethers linking them. In all the software tools, the kites or tethered fixed-wing drones are represented as rigid bodies and the dynamic equations of the tether-bridle-vehicle systems, together with the user-defined and time-dependent control variables, are solved self-consistently. Academic and research analysis can take advantage of the modularity of the simulators and their inputs and outputs interfaces, which follow a common and user-friendly architecture.This work was supported by the Ministerio de Economía, Industria y Competitividad of Spain and the European Regional Development Fund under the project ENE2015-69937-R (MINECO/FEDER, UE). GSA work is supported by the Ministerio de Economía, Industria y Competitividad of Spain under the Grant RYC-2014-15357. RS is acknowledging the receipt of funding from the European Unions Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 642682 for the ITN project AWESCO and the grant agreement No. 691173 for the Fast Track to Innovation project REACH.Publicad
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