1,720,984 research outputs found
A Paper-based potentiometric sensor for solid samples: corrosion evaluation of reinforcements embedded in concrete structures as a case study
No full textHerein, we present the first paper-based device for facing one of the worldwide concerns of the Modern age: the corrosion-induced deterioration of reinforced concrete. Indeed, the monitoring of corrosion extent in reinforced concrete constructions has been acknowledged as a priority for public safety. In this work, the porosity properties of a paper-based screen-printed Ag/AgCl electrode were exploited for realising a smart analytical tool to be directly applied on the solid surface of concrete for the evaluation of corrosion. The analysis was carried out by measuring the electrochemical potential between the metallic reinforcement and the sensor, needing only 70 μL of electrolyte solution. The sensor was firstly tested in the laboratory using reinforced concrete samples and then applied on the real outdoor artwork Music Collection Session by Arman (Milan, Italy). A summary of the main available non-destructive techniques for corrosion monitoring is reported to provide a critic overview
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
Multiparametric analysis by paper-assisted potentiometric sensors for diagnostic and monitoring of reinforced concrete structures
No full textReinforced concrete has been employed worldwide as a leading building material for public and private structures as well as in modern sculptural art. Although the unrivalled mechanical strength and modelling versatility of this material, several interrelated processes are responsible for its progressive degradation (e.g., carbonation, penetration of aging-promoting agents), decreasing its long-last durability and representing a risk for the public security or the cultural heritage. With the aim to tackle this issue, the present work reports a novel configuration of a screen-printed sensor, obtained by the combination of flexible and robust polyester support and wax-printed filter paper device for the direct application on the concrete surface. Our sensor consists of a polyester-printed three-electrochemical cell that allows dual measurements on reinforced concrete, namely (i) the evaluation of corrosion probability of the metallic reinforcements (which outperforms the half-cell potential standard method) and (ii) the employment of a pH-sensitive iridium oxide film for the measurement of the pH of concrete. The paper was used as a porous material capable of ensuring the electrochemical connection between the Ag/AgCl printed electrode and the concrete solid matrix, acting also as a protective envelope for the electrode. After the laboratory tests, which revealed the noteworthy performances of the sensors in distinguishing among different levels of corrosion as well as measuring the pH of concrete, the developed sensor was applied for on-site measurement at the Giacomo Manzu Museum (Ardea, Italy), demonstrating its suitability for the real application to cultural heritage conservation. Overall, this easy-to-handle and non-invasive diagnostic device provides an innovative analytical approach for the on-site and prompt multiparametric monitoring of the physico-chemical phenomena that endanger the long-lasting preservation of reinforced concrete structures
Monitoraggio della corrosione nelle barre di rinforzo per le strutture in cemento armato
No full textIn Italia l'interesse per il monitoraggio strutturale è recentemente aumentato, anche in conseguenza di alcuni drammatici crolli di importanti infrastrutture. Spesso la valutazione della salute di una struttura è il risultato della valutazione visiva da parte di esperti, almeno inizialmente. Il cemento armato è uno dei materiali da costruzione più adottati per le infrastrutture e gli edifici, nell'ultimo mezzo secolo, ma la sua durabilità è in grande discussione, anche perché legata alla condizione delle barre metalliche dell’armatura. In condizioni normali le barre sono protette dalla corrosione in quanto circondate dalla matrice di calcestruzzo. Ma quando l’alcalinità del calcestruzzo diminuisce rispetto al suo valore ottimale, per vari motivi, le barre di armatura sono a rischio corrosione. Questo documento si propone di mostrare come sia possibile monitorare le condizioni delle barre di rinforzo in acciaio utilizzando sensori elettrochimici stampati miniaturizzati ed economici combinati con strumentazione portatile. Sebbene tale attività non fornisca al momento una valutazione quantitativa del danno strutturale, sembra almeno fornire informazioni particolarmente rilevanti per monitoraggi ulteriori sulle condizioni del materiale, sollecitando le contromisure di ripristino per estendere la durata e la sicurezza della struttura
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
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