1,721,422 research outputs found
The Crust-Mantle and Lithosphere-Asthenosphere Boundaries: Insights from Xenoliths, Orogenic Deep Sections, and Geophysical Studies
No full textThis volume encompasses contributions from a wide spectrum of earth science disciplines, including geophysics, geodynamics, geochemistry, and petrology, to provide an overview of the nature and evolution of the crust-mantle and lithosphere-asthenosphere boundaries in different tectonic settings
The potential impact of municipal solid waste incinerators ashes on the anthropogenic osmium budget
No full textOsmium release from Municipal Solid Waste Incinerators (MSWI), even if acknowledged to occur at least over the last fifteen years, remains overlooked in the majority of recent studies. We present the osmium concentration and (187)Os/(188)Os isotopic measurements of different kinds of bottom and fly ash samples from MSWI plants and reference materials of incinerator fly ash (BCR176 and BCR176R). The analysis of the unknown ash samples shows a relatively wide range of (187)Os/(188)Os ratios (0.24-0.70) and Os concentrations (from 0.026ng/g to 1.65ng/g). Osmium concentrations and isotopic signatures differ from those of other known Os sources, either natural or manmade, suggesting a mixture of both contributions in the MSWI feedstock material. Furthermore, the comparison between the BCR176 and the renewed BCR176R indicates a decrease in Os concentration of one order of magnitude over the years (from 1 to 0.1ng/g) due to improved recycling efficiency of Os-bearing waste. The estimated annual amount of Os from a typical incinerator (using average Os values and MSWI mass balance) is 13.4g/a. The osmium potentially released from MSWI smokestacks is predicted to be from 16 to 38ng Os/m(2)/a, considering a medium size country having 50 MSWI facilities; therefore much higher than the naturally transported osmium from continental dust in the atmosphere (about 1pg Os/m(2)/a). MSWI systems are considered one of the best options for municipal solid waste management in industrialised countries, but their contribution to the Os budget can be significant
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
The sondalo gabbroic complex (central alps, Northern Italy): evidence for emplacement of mantle-derived melts into amphibolite-facies metapelites
No full textThe Sondalo gabbroic complex is related to the magmatic event that postdated the Variscan orogeny. The complex mainly consists of gabbronorites, associated with subordinate amounts of olivine-gabbros, and minor quartzdiorites. These rocks can be related to tholeiitic liquids that underwent a differentiation process controlled by fractional crystallisation and concomitant assimilation of crustal
material. Basement country rocks are mostly made of twomica
amphibolite-facies metapelites that are locally sillimanite-bearing. Close to the contact with the gabbroic complex, the metapelites display migmatitic fabric. Melanosomes show the consumption of muscovite and the development of sillimanite and anhedral garnet. Leucosomes are quartz-feldspathic in composition and locally
characterised by the growth ofporphyroblastic garnet. Contact
migmatites are in places characterised by the presence of
peraluminous granitoid pods. Large xenolith blocks (up to
hundreds of meters in size) showing granulite-facies assemblages, as well as peraluminous granitoid dykes, crop out within the gabbroic complex. The xenolith blocks are volumetrically dominated by cordierite- and sillimanite bearing garnet-rich rocks. These rocks are characterised by low silica and alkalis, and high AI203, Fe203 ~t, MgO, TiO2 and MnO. These chemical features are interpreted to reflect a restitic origin, related to the extraction of"granitic" liquids from metapelitic sources. The garnet-rich xenolith blocks are discontinuosly wrapped by bodies of garnet-hearing mafic rocks. The Sondalo gabbroic complex resulted from the intrusion of mantle-derived liquids into intermediate levels
of the continental crust. Such intrusion did not lead to regional
granulite-facies metamorphism and triggered melting processes in contact metapelites. Extraction of anatectic liquids gave rise to dense restitic blocks that could sink into the magma chamber, where they possibly underwent further melting
Dental Adhesives-Surface Modifications of Dentin Structure for Stable Bonding
No full textThe latest advancements in dentin bonding have focused on strategies to impair degradation mechanisms in order to extend the longevity of bonded interfaces. Protease inhibitors can reduce collagen degradation within the hybrid layer (HL). Collagen cross-linkers allow better adhesive infiltration and also inhibit proteases activity. Particles added to adhesive can promote mineral precipitation within the HL, reducing nanoleakage and micropermeability, besides possible antimicrobial and enzymatic inhibition effects. Most of these approaches are still experimental, and aspects of the adhesive under the clinician's control are still determinant for the long-term stability of adhesive restorations
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