1,720,958 research outputs found
An innovative application of optical tecniques in Cultural Heritage for the characterization of carbonaceous fraction in atmospheric particulates
No full textMicro-Raman depth profiling on polished cross section: the mapping of oxalates used in protective treatment of carbonatic substrate
No full textWe present the first depth profiling on a polished cross-section carried out by micro-Raman spectroscopy aimed at investigating the penetration depth of an inorganic protective material (ammonium oxalate) applied on carbonatic surfaces (ancient plaster) and to detect the distribution of mineralogical phases inside the material. The reason for such a Rapid Communication is the importance of our study for the field of conservation, in which at present the treatment with oxalates is a hot issue
pi-Electron Delocalization and Raman Spectra in Graphite and Graphene Molecules: The Role of the Edges in Graphene Sheets
No full textRaman studies of molecular graphites
No full textcontributo orale al meeting della European Materials Research Society (primavera 2009
Preliminary observation on the interactions between fine atmospheric particulate matter (PM2.5) and human alveolar epithelial cells (A549)
No full textFine atmospheric particulate matter (PM2.5) was collected in Milan during winter at Torre Sarca site, representative of background urban atmospheric pollution concentrations. Human alveolar epithelial A549 cells were subsequently exposed to
different particle doses for increasing time. PM2.5 morphology, as well as cell-particle interaction, were characterized by light microscopy, transmission electron microscopy and Raman spectroscopy. Based on previous theoretical studies of molecular dynamics and vibrational spectroscopy (Zerbi et al. 2006, Zerbi 2007) we developed a method to extract from the Raman spectra information on the molecular properties of different carbonaceous materials. It has been shown that PM2.5 is progressively internalized in cells (Gualtieri et al., 2007). Of particular interest is the preliminary observation that the Raman spectra of a carbon particulate (PM2.5) isolated from its surrounding or encapsulated in a cellular matrix, like that of alveolar epithelial cells, showed differences. It indicates that some kind of interaction at the molecular level has occurred. Further work is in progress
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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