1,721,417 research outputs found
Automotive spent catalysts treatment and platinum recovery
No full textThe recovery of Platinum from spent catalysts was examined. Platinum leaching was studied considering particle size, temperature, solid-liquid and HCl/ HNO3 ratio effects. Many elements together with Pt were taken from a mixed spent catalyst sample. The main components of the leach liquor were Pt (1.84 g/ kg cat) and Fe (0.94 g/kg cat). Platinum was separated from the leach aqueous solution by using Tri-Octyl Phosphine Oxide (TOPO) in kerosene. The extraction was studied considering equilibrium time, TOPO and HCl concentration, tin(II) chloride presence and stripping agents. Iron represents the main ion competitor for Pt extraction. Copyright © 2013 Inderscience Enterprises Ltd
Cobalt and manganese recovery from spent industrial catalysts by hydrometallurgy
No full textIn the present work, hydrometallurgical techniques were applied in order to recover cobalt and manganese from fly ash coming from incineration of spent industrial catalysts. Washing steps with water were carried out, with the aim of removing the soluble salts. The residue was leached in order to establish the optimal operative conditions. Cobalt/manganese separation was investigated by solvent extraction, using Cyanex 301 in kerosene as an extractant varying pH, extractant concentration and organic/aqueous volume ratio. Stripping tests were performed to re-extract cobalt ions in a new aqueous phase, employing hydrochloric acid as stripping agent. The proposed process allows to recover 99.7% of cobalt and 86.6% of manganese. © 2013 Taylor & Francis Group
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
Materials recovery from waste liquid crystal displays: A focus on indium
No full textIn the present work the recovery of indium and of the polarizing film from waste liquid crystal displays was experimentally investigated in the laboratory. First of all, the polarizing film was removed by employing a number of different techniques, including thermal and chemical treatments. Leaching of indium was then performed with HCl 6. N, which allowed solubilisation of approximately 90% In (i.e. 260. mg In per kg of glass) at room temperature, without shredding. Indium recovery from the aqueous phase was then investigated through solvent extraction with polyethylene glycol (PEG)-based aqueous biphasic systems. Indium extraction tests through the PEG-ammonium sulphate-water system were conducted as a function of PEG concentration, salt concentration and molecular weight of PEG, using 1,10 phenanthroline as a ligand. The experimental results demonstrated that indium partitioning between the bottom (salt-rich) and the top (PEG-rich) phase is quite independent on the composition of the system, since 80-95% indium is extracted in the bottom phase and 5-20% in the top phase; it was also found that when PEG concentration is increased, the ratio between the bottom and the upper phase volumes decreases, resulting in an increase of indium concentration in the bottom phase (at [PEG]. = 25% w/w, indium concentration in the bottom phase is ~30% higher than the initial concentration before the extraction). © 2015 Elsevier Ltd
“Modellistica del clima : generazione di grandezze meteoclimatiche probabili a partire da pochi dati sintetici caratteristici del luogo”
No full textVariations 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
Lenti, macchine fotografiche e voyeurismo intertestuale: il buco dello sguardo nell’Oblò di Adriano Spatola
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