1,721,015 research outputs found
Effect of Different Carbon blacks on the Simultaneous Electroanalysis of Drugs as Water Contaminants based on screen-printed sensors.
No full text:For the construction of the sensor, three different carbon black (CB) materials (VULCAN XC72R, BLACK PEARLS 4750 and CB N220) were explored as modifying nanomaterial. Firstly, the electrochemical activity of the each SPE modified was compared by cyclic voltammetry and electrochemical impedance spectroscopy technique, using [Fe(CN)6] 3 /4 as redox couple. After demonstrating that electrodes modified with different types of CB were characterized by improved electrochemical performances when compared with bare electrodes, and among them, electrodes modified with CB BP4750 is characterised by slightly better electrochemical properties, this type of electrode was used for the development of the analytical method. By applying SWV technique in 0.2 molL 1 phosphate buffer (pH 3.0), the obtained analytical curves for ACP and LVF were found linearly from 4.0 to 80.0 μmolL 1 and from 0.90 to 70.0 μmolL 1 with limit of detection of 2.6 μmolL 1 and 0.42 μmolL 1 for ACP and LVF, respectively. Finally, the quantification of these drugs in river water was evaluated using the new here-proposed sensor by recovery method in spiked samples, obtaining satisfactory recovery values. The results achieved demonstrated that the developed analytical tool is of great analytical interest being easy to use, cost-effective, miniaturized, and thus suitable for low cost on site analysys
Electrochemical determination of capsaicin in pepper samples using sustainable paper-based screen-printed bulk modified with carbon black
No full textSustainable development goals reported in 2030 Agenda established the global challenges in different fields including agrifood, health, and climate change. Smart electrochemical eco-designed sensors can support the achievement of some goals thanks the capability to detect analyte on site using cost-effective instrumentation by unskilled personnel. Herein, we report the first office paper-based sensor fabricated by merging cost-effective technique namely screen- and wax-printing with cheap materials namely paper and carbon black for sustainable detection of capsaicin. By using differential pulse and square wave voltammetry capsaicin was detected at potential close to 0.5 V observing a linear range from 0.20 to 8.0 μmol L−1 and from 0.080 to 6.0 μmol L−1, sensitivity of 1.11 A mol−1 L and 1.97 A mol−1 L, and detection limit of 0.085 μmol L−1 and 0.028 μmol L−1, respectively. The accuracy of the paper-based device was assessed determining capsaicin in tabasco sauce, black pepper, and red pepper by recovery study, obtaining recovery values ranging from 93% to 110%. The analytical features achieved demonstrated the suitability of this paper and carbon black-based analytical tool for application in agrifood sector, boosting the sustainable management of quality control in food commodities
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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