1,720,960 research outputs found
Observations and box-model analysis of Radon-222 in the atmospheric surface layer at L’Aquila, Italy: March 2009 case study
No full textTwo years of Radon-222 observations collected at L’Aquila (Italy) in the atmospheric surface layer during 2004-2006 have been analysed in correlation with meteorological data and other atmospheric tracers. A box model has been developed to better understand the mechanisms for diurnal and seasonal variability of the tracer and to indirectly assess the magnitude of the monthly averaged radon soil flux in the L’Aquila measurement site. The model has been successfully validated with measurements, with a 0.8 average correlation coefficient between hourly values for the whole period of radon observations. Measurements taken during March 2009 have been analysed to find possible signs of perturbation due to the on-going seismic activity that would have reached its peak in the April 6, 2009 destructive earthquake. Contrary to professed (and unpublished) dramatic increases of radon activity unofficially announced to the inhabitants at that time, the study presented here shows that no radon activity increase was taking place in L’Aquila with respect to a previous ‘seismically-unperturbed’ year (same month with similar meteorological conditions), but also experienced an average 30% decrease. This conclusion is reached from a direct comparison of observed data, but also as a result of the previously validated radon box model constrained by actual meteorological data, where an indirect estimate of a 17% reduction of the radon soil flux is obtained from
RIFLESSIONI MEDICO - LEGALI SU DI UN CASO DI RESPONSABILITà PROFESSIONALE DELL'ORTOPEDICO CONSEGUENTE AD INTERVENTO DI OSTEOSINTESI CON FISSATORE ESTERNO
No full textAtmospheric radon in the surface layer: a box model constrained with meteorological data
No full textIn situ measurements of Radon-222 in the atmospheric surface layer collected at L’Aquila (Italy) during 2004-2009 have been analyzed in correlation with meteorological data and other atmospheric trace gases. These data have been studied in order to find the controlling mechanisms of surface radon abundance: observations of coincident meteorological parameters confirmed the important role of small-scale atmospheric dynamics. The negative correlation of hourly data of surface wind speed and radon activity concentration, as well as of ozone and radon abundances, suggests that dynamical removal of radon is one of the most important controlling processes of the tracer accumulation in the atmospheric surface layer. A box model has been developed to better understand the mechanisms for diurnal and seasonal variability of the tracer and to indirectly assess the magnitude of the monthly averaged radon soil flux in the L’Aquila measurement site. The model has been successfully validated with measurements: on average for the whole period of observations, the correlation coefficient of measured and modelled radon hourly data is 0.8. Radon data collected during March 2009 have also been analyzed to find possible signs of perturbation due to the on-going seismic activity that would have reached its peak in the April 6, 2009 destructive earthquake. However, the present study shows that no significant radon activity increase was taking place in L’Aquila at that time with respect to a previous ‘seismically-unperturbed’ year, during the same month with similar meteorological conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
