1,721,011 research outputs found
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
Host-guest Chemistry in the Gas Phase and at the Gas-solid Interface: Fundamental Aspects and Practical Applications
No full textThe study of host-guest interactions has recently expanded from solution chemistry to the gas phase, where solvent effects are not present, allowing better understanding of the intrinsic phenomena responsible for molecular recognition. Important aspects under investigation include the mechanism of interaction, the identification of binding groups, as well as the discovery of structural requirements for the host to undergo inclusion complexation. The information gained from these gas phase studies can be exploited to design new practical applications of host-guest chemistry, particularly when gas-solid interactions are involved. Analytical devices such as gas sensors and chromatographic adsorbing cartridges take advantage of the structural recognition capability of the host to achieve high levels of selectivity
METHOD FOR PREPARING ENDOSSEOUS IMPLANTS WITH ANATASE TITANIUM DIOXIDE COATING.
No full textThe method includes the following steps: formulation of liquid, non-gelled and stable precursor by solvolysis of Ti(IV) compounds; precursor deposition on endosseous implant surface; thermal treatment to achieve film densification, in the presence of oxygen, of a complex formed by the above mentioned endosseous implant and precursor, to obtain on the implant surface a thin film of nanocrystalline titanium dioxide with good mechanical and chemical stability; The complex above, under a persistent UV irradiation modify its surface status conferring a sensible increasing of wettability chemical and biological decontamination
Diffusion processes in amphiphilic aggregate systems
No full textThe diffusion properties of aggregates of amphiphilic mols. (e.g., micelles, microemulsion) are discussed. The interaction of these organized assemblies with water-sparingly sol. org. compds. and ions and the consequent influence on the transport of these species is examd. as well as their effect on the transfer of solutes through a membrane
Voltammetry of quinones in anionic micelles
No full textA voltammetric study of a series of differently substituted benzenediols was carried out in aq. anionic micellar solns. The partitioning of the probes between the bulk aq. and the micellar pseudophase affects both the obsd. currents and the half-wave potentials. The results are discussed in terms of probe-aggregate interactions and compared with kinetics of electron transfer reactions involving benzenediol/quinone couples
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
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