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Prove sperimentali di pre-sonicazione nella rimozione del mercurio in fanghi di dragaggio della laguna di Grado-Marano
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Effect of low frequency ultrasounds on desorption of mercury from solid matrices (a case study in north-east Italy).
No full text“Synthesis and Characterization of a New Pentaphyrin Macrocycle as Potential Photosensitizer.”
No full textSalt assisted and sonolitic supported thermal desorption of mercury from polluted dredging sludge
No full textSalt-assisted thermal desorption of mercury from contaminated dredging sludge
No full textIn this study, we tested a new procedure for the decontamination of mercury-polluted dredging sludge
(Marano-Grado Lagoon, northeastern Italy) based on cationic exchange associated with thermal desorption
at a low temperature. Four mercury-polluted sludge slurries were treated using thermal desorption
at 393 K for 2 h. Three different salts, NaCl (sodium chloride), (CH3)4NCl (tetramethylammonium chloride)
and (C4H9)4NCl (tetrabutylammonium chloride) were used as exchangers. The selected salts have a
monovalent cationic part that progressively increases in molecular weight. The results show that the association
of cationic exchange with thermal treatment leads to a significant improvement in the removal of
mercury from the contaminated material at a low temperature compared to samples that were not treated
with salt. The highest levels of decontamination were attained were obtained when the slurries, which
had mercury pollution ranging from 20 to 200 ppm, were treated with a 15% solution of (C4H9)4NCl. The
efficiency of the removal at 393 K (from 24% up to 60%) depended on the nature of the sample. When the
samples were treated at a similar temperature without the salt, no remediation of mercury was detected.
Our results show that the thermal decontamination temperature can be significantly lowered by this
remediation approach, which is the first example based on cationic exchange of the pollutant with an
appropriate salt
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
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