1,720,976 research outputs found
Un modello lagrangiano per il calcolo delle fluttuazioni della concentrazione di inquinanti passivi
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MODELLING POLLUTANT REACTIONS DEPENDING ON INSTANTANEOUS CONCENTRATIONS: A DIRECT ESTIMATION OF THE SEGREGATION COEFFICIENT
No full textWe have implemented a reaction scheme, based on the conserved scalar theory, into a Lagrangian
micromixing model (LAGFLUM, Leuzzi et al.). This coupled solution is tested in decaying grid turbulence to
represent the dispersion of reactive pollutants. We report preliminary validations, obtained by comparisons with
available measurements and analytical solutions, as well as several model inter-comparisons. We underline the
difference between modelling pollutant reactions depending on the instantaneous instead of the mean concentrations
of the reactants (effects of the segregation coefficient). Finally, we have implemented and tested a new limit for the
scalar conserved theory, which tries to improve the reaction-dominated limit (RDL) in non-homogeneous conditions
Un modello numerico per la previsione della dispersione di inquinanti nella città di Roma
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
An urban scale study of pollutant dispersion in Rome
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A Gaussian model software (Atmospheric Dispersion Model System –ADMS-Urban) is used to forecast the Carbon Monoxide (CO) concentrations in the Urban Boundary Layer (UBL) of the city of Rome, Italy. The simulations refer to 14 days during 2002.
Two data set inputs were considered in order to evaluate the urban background concentration and the effects of the main roads surrounding the monitoring stations. Results show that the background concentration plays a fundamental role in the whole balance of the pollution and that sometimes it overcomes the level associated to the local emissions. Finally, the background concentration appears to be strongly non-homogeneous within the urban area
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