1,720,987 research outputs found
Nanostructured catalysts production through electrochemical methods: synthesis, characterization and possible applications
Full text linkIn this work a study of the electrochemical synthesis of TiO2 based nanostructured electrodes for photocatalytic and electrocatalytic applications is presented.
The study on the electrochemical synthesis of TiO2 nanotubes (NTs) through anodization has been aimed to develop a novel “single-step” anodization method in symmetric electrochemical cells (i.e. both electrodes are Ti sheets), instead of traditional “double-step” processes, which include the sequence of two anodizations separated by the dissolution of the first formed TiO2 and are carried out in asymmetric cells with Pt electrocatalysts as counter electrodes.
Besides the anodization, in relation to the specific applications discussed in this study, further electrochemical synthesis routes, employing the anodized TiO2 electrodes, were investigated.
In photocatalytic applications, the electrodeposition of Cu2O nanoparticles over the surface of TiO2 NTs has been adopted as strategy to overcome the limited light absorption of the bare TiO2 photocatalyst (active only under UV irradiation). Here, in agreement with most of the studies among the available literature, under visible irradiation the TiO2/Cu2O based electrodes showed improved performances than the bare TiO2 (inactive under only visible light). These improved performances have been frequently claimed based on the only analysis of the photocatalytic performances under visible light, while in the present study it was found that, when the light source employed was UV + visible rather than only visible, the photo-catalytic performances of the composite electrodes were lower as compared to the bare TiO2 electrode. Furthermore, the bare TiO2 activity registered under UV + visible was higher than the composite electrode activity registered under only visible irradiation. To overcome this unexpected behaviour, at this stage the study has been aimed to the development of photo/electrochemical post-treatments, which allowed to improve the performances of the Cu2O based electrodes also under UV + visible light.
Black TiO2 electrocatalysts were finally synthesized in the framework of the activities related to the e.THROUGH EU project (H2020-MSCA-RISE-2017-778045), which is aimed to the recovery of critical raw materials and sustainable remediation.
Briefly, this goal would be achieved through the development of electrokinetic technologies for soil remediation, as in the case of the electrodialytic mine tailings remediation performed in this work. Electrodialytic remediation is generally carried out in symmetric cells which employ commercial Ti/MMO (Mixed Metal Oxides; Ir/Ru-based) electrodes, for both anode and cathode. Main limit for the real employment of these technologies are the energy costs related to the stirring and the power supply. Here, considering that the main reactions involved during the process are the water splitting reactions, one of the strategies to minimize the overall process cost is based on the recovery of the produced hydrogen. Considering that Ir-/Ru- based compounds are benchmark catalysts for the anodic reaction involved rather than the cathodic hydrogen evolution reaction, at this stage, the study has been aimed to the development of a non-commercial hydrogen evolution reaction (HER) electrocatalyst, namely the Black TiO2 based electrodes. These electrodes have been synthesized through the electrochemical reduction of the Ti/TiO2 electrodes resulting from the anodization, employing Ti sheets as counter electrodes
Monitoraggio di BTEX in uno street canyon profondo
No full textE’ stata condotta una campagna di monitoraggio di BTEX (benzene, toluene, etilbenzene, m- p- e o-xilene) in uno street canyon profondo nell’area urbana di Napoli. I prelievi sono stati effettuati utilizzando cartucce adsorbenti. In simultanea si sono effettuate misure del traffico e dei parametri meteorologici. Dai risultati è emerso che i livelli di concentrazione di benzene hanno superato, per circa un quarto dei campionamenti, il limite imposto per l’anno 2007 dalla Comunità Europea, pari a 8 μg/Nm3. La correlazione tra i livelli di concentrazione dei BTEX e le emissioni veicolari è risultata bassa. I valori più elevati del coefficiente di correlazione si sono riscontrati per le emissioni dei veicoli a due ruote. La differenza di concentrazione sui due lati della strada, valutata mediante un’analisi statistica, è risultata non significativa. Quest’ultimo risultato può essere di particolare interesse per lo sviluppo di modelli parametrici specifici per street canyon profondi
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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