87,126 research outputs found
Fluorine in the solar neighborhood : Chemical evolution models
No full textContext. In light of new observational data related to fluorine abundances in solar neighborhood stars, we present chemical evolution models testing various fluorine nucleosynthesis prescriptions with the aim to best fit those new data. Aim. We consider chemical evolution models in the solar neighborhood testing various nucleosynthesis prescriptions for fluorine production with the aim of reproducing the observed abundance ratios [F/O] versus [O/H] and [F/Fe] versus [Fe/H]. We study in detail the effects of various stellar yields on fluorine production. Methods. We adopted two chemical evolution models: the classical two-infall model, which follows the chemical evolution of halo-thick disk and thin disk phases; and the one-infall model, which is designed only for thin disk evolution. We tested the effects on the predicted fluorine abundance ratios of various nucleosynthesis yield sources, that is, asymptotic giant branch (AGB) stars, Wolf-Rayet (W-R) stars, Type II and Type Ia supernovae, and novae. Results. The fluorine production is dominated by AGB stars but the W-R stars are required to reproduce the trend of the observed data in the solar neighborhood with our chemical evolution models. In particular, the best model both for the two-infall and one-infall cases requires an increase by a factor of 2 of the W-R yields. We also show that the novae, even if their yields are still uncertain, could help to better reproduce the secondary behavior of F in the [F/O] versus [O/H] relation. Conclusions. The inclusion of the fluorine production by W-R stars seems to be essential to reproduce the new observed ratio [F/O] versus [O/H] in the solar neighborhood. Moreover, the inclusion of novae helps to reproduce the observed fluorine secondary behavior substantially
Ryde Town Hall Estate [cartographic material] : auction sale on the ground at 3 p.m., Sat. 4th. November 1916 /
No full textSales plan for land in Ryde in Sydney, New South Wales, bounded by Parkes Street, Argyle Avenue and Princess Street.; "Terms: 3 deposit per lot, balance in 60 monthly payments, interest 6% payable quarterly."; "Torrens title."; "Solicitors to the Estate, Russell & Russell, 350 George St. City."; "Licensed surveyor R.P. Act, Percy G. Chatfield, Ryde."; Includes text on verso.; Also available in an electronic version via the internet at: http://nla.gov.au/nla.map-lfsp2480
Fluorine in the solar neighbourhood : modelling the Galactic thick and thin discs
No full textWe investigate the evolution of the abundance of fluorine in the Milky Way thick and thin discs by means of detailed chemical evolution models compared with recent observational data. The chemical evolution models adopted here have already been shown to fit the observed abundance patterns of CNO and alpha-elements as well as the metallicity distribution functions for the Galactic thick and thin disc stars. We apply them here to the study of the origin and evolution of fluorine, which is still a matter of debate. First, we study the importance of the various sites proposed for the production of fluorine. Then, we apply the reference models to follow the evolution of the two different Galactic components. We conclude that rotating massive stars are important producers of F and they can set a plateau in F abundance below [Fe/H]=-0.5 dex, though its existence for [Fe/H]<-1 has yet to be confirmed by extensive observations of halo stars. In order to reproduce the F abundance increase in the discs at late times, instead, a contribution from lower mass stars - single asymptotic giant branch stars and/or novae - is required. The dichotomy between the thick and thin discs is more evident in the [F/O] versus [O/H] plot than in the [F/Fe] versus [Fe/H] one, and we confirm that the thick disc has evolved much faster than the thin disc, in agreement with findings from the abundance patterns of other chemical elements
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Ryde Unity, mobility for all, tourism without barriers
No full textRyde Unity aborda los desafíos de accesibilidad y desplazamiento que enfrentan las Personas con Movilidad Reducida (PMR) al visitar los pueblos patrimonio de Colombia, permitiéndoles disfrutar de experiencias de viaje sin barreras. Se logró mediante el rediseño e implementación de un cambio estructural en los Moto taxis, medio de transporte tradicional de los pueblos en Colombia, facilitar el acceso y movilización de las PMR. Para llegar al producto final, se hizo recolección de información, con el pueblo de Jericó Antioquía, que es uno de los 18 pueblos patrimonio de Colombia, durante aproximadamente una semana. Allí con la comunidad Jericoana, se obtuvo información de peso y valor, directamente de las personas que hacen uso de este medio de transporte y que harían uso de Ryde Unity, Además de mejorar la calidad de vida de las personas con movilidad reducida, este proyecto contribuye al fomento del turismo inclusivo, promoviendo la igualdad de oportunidades y la diversidad en la industria turística.Diseñador IndustrialPregradoRyde Unity addresses the challenges of accessibility and mobility faced by People with Reduced Mobility (PRM) when visiting the heritage towns of Colombia, allowing them to enjoy
barrier-free travel experiences. This was achieved through the redesign and implementation of a structural change in mototaxis, the traditional means of transportation in Colombian
towns, to facilitate access and mobility for PRM. To reach the final product, information was collected in the town of Jericó, Antioquía, which is one of the 18 heritage towns of Colombia,
over the course of approximately one week. Valuable and significant information was gathered directly from the Jericó community, specifically from the people who use this mode of transportation and who would benefit from Ryde Unity. In addition to improving the quality of life for people with reduced mobility, this project contributes to the of inclusive tourism, fostering equal opportunities and diversity in the tourism industr
North Beach estate, Manly, opposite North Steyne [cartographic material] /
No full text"Percy G. Chatfield, surveyor to estate, Ryde".; Sales plan of North Beach estate, Manly
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Modelling the chemical evolution of Zr, La, Ce, and Eu in the Galactic discs and bulge
No full textWe study the chemical evolution of Zr, La, Ce, and Eu in the Milky Way discs and bulge by means of chemical evolution models compared with spectroscopic data. We consider detailed chemical evolution models for the Galactic thick disc, thin disc, and bulge, which have been already tested to reproduce the observed [α/Fe] versus [Fe/H] diagrams and metallicity distribution functions for the three different components, and we apply them to follow the evolution of neutron capture elements. In the [Eu/Fe] versus [Fe/H] diagram, we observe and predict three distinct sequences corresponding to the thick disc, thin disc, and bulge, similar to what happens for the α-elements. We can nicely reproduce the three sequences by assuming different time-scales of formation and star formation efficiencies for the three different components, with the thin disc forming on a longer time-scale of formation with respect to the thick disc and bulge. On the other hand, in the [X/Fe] versus [Fe/H] diagrams for Zr, La, and Ce, the three populations are mixed and also from the model point of view there is an overlapping between the predictions for the different Galactic components, but the observed behaviour can be also reproduced by assuming different star formation histories in the three components. In conclusions, it is straightforward to see how different star formation histories can lead to different abundance patterns and also looking at the abundance patterns of neutron capture elements can help in constraining the history of formation and evolution of the major Galactic components
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
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