1,721,001 research outputs found
Electrochemical sensor for indirect detection of bacterial population
No full textA homemade ultra-microelectrodes array based on reticulated vitreous carbon (RVC) has been used to monitor the bacterial load
(Staphylococcus aureus) coupling electrochemical and chemometric methods. Normal pulse voltammograms (NPV), recorded in filtered solutions, where different amounts of S. aureus had been inoculated, have been analyzed with partial least squares (PLS) regression. Useful signals at selected potentials, chosen with iterative prediction weighting method, were fitted by PLS. The method permits to model the
bacterial concentration with respect to the electrochemical current response. The technique seems to work well down to 1 or 2 cells/ml (most probable number method estimation) of inoculated bacteria
Electrochemical behavior of Inhcf in alkali metal electrolytes
Full text linkThe paper characterizes electrochemical properties
of indium hexacyanoferrates (Inhcf). The cyclic
voltammetric response in the presence of different metal
alkali cations of divalent cations and of hydronium has been
investigated. The Inhcf can exchange reversibly with all of
these cations. This feature makes the Inhcf a good candidate
for many electrochemical applications where a source or
sink of metal cations is needed, e.g., electrochromic and
energy storage devices. A prototype electrochromic system
based on an Inhcf and Cohcf couple has been assembled and
tested
An Overview on the Facile and Reversible Cations Intercalation in Nickel-Hexacyanoferrate Open Framework
Full text linkThe paper reports a detailed study about the influence of the electrolyte composition in nickel-
hexacyanoferrate (NiHCF) electrochemical behavior. Shapes and positions of the CV waves are
strongly related to the cation of the supporting electrolyte, which undergoes intercalation/de-
intercalation during the redox process. The electrochemical behavior of NiHCF has been characterized
in different electrolyte solutions containing either pure monovalent or trivalent metal nitrates. Nickel-
hexacyanoferrate permits the reversible insertion of a wide variety of monovalent, divalent and
trivalent ions in aqueous solution; the characteristic potential Ep of the cathodic process depends upon
the nature of the intercalated cation. Electrochemical measurements demonstrate the unprecedented
fast kinetics of trivalent ion insertion associated with this material. The reported findings represent the
first systematic step toward understanding the principles of multivalent charge screening and provide a
novel cation intercalation mechanism in NiHCF, assisted by both water molecules and ferrocyanide
vacancies. The synergistic mechanism can reduce the electrostatic repulsion and provide a preferential
path for the rapid cation intercalation
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
Immobilization of nanobeads on a surface to control the size, shape and distribution of pores in electrochemically generated sol-gel films
Full text linkElectrochemically assisted deposition of an ormosil film at a potential where hydrogen ion is generated as the catalyst yields insulating films on electrodes. When the base electrode is modified with 20-nm poly (styrene sulfonate), PSS, beads bound to the surface with 3-aminopropyltriethoxysilane (APTES), and using (CH3) 3SiOCH3 as the precursor, the resulting film of organically modified silica (ormosil) has cylindrical channels that reflect both the diameter of the PSS and the distribution of the APTES-PSS on the electrode. At an electrode modified by a 20-min immersion in 0.5 mmol dm−3 APTES followed by a 30-s immersion in PSS, a 20-min electrolysis at 1.5 V in acidified (CH3) 3SiOCH3 resulted in an ormosil film with 20-nm pores separated by 100 nm. Cyclic voltammetry of Ru (CN) 6 4− at scan rates above 5 mV s−1 yielded currents controlled primarily by linear diffusion. Below 5 mV s−1, convection rather than the expected factor, radial diffusion, apparently limited the current
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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