1,721,089 research outputs found
Mr. George Bush [Account with] Samuel Baker, Dr.
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/239310For loads of Stones taken to Baldwin Street [Bristol].129626
Sub-Item: [1980.0075.04327] "Mr. George Bush [Account with] Samuel Baker, Dr.
Halogens in volcanic systems
No full textThe transport, degassing and atmospheric release of halogens from active volcanism on Earth have been the 12 focus of increasing interest over the last few decades, and have recently been the subject of the 1st workshop 13 on “Halogens in volcanic systems and their environmental impacts” that was held in December of 2007 at 14 Yosemite Lodge in Yosemite National Park, California. As an introduction to this Chemical Geology special 15 issue, collecting contributions from many of the participants at the workshop, we review here recent 16 advances in this field, including experimental and theoretical investigations of halogen behaviour in volcanic 17 and related magmatic systems. We discuss previous research on several aspects of halogen geochemistry, 18 including halogen abundances in the mantle and magmas on Earth; the effects of halogens on phase 19 equilibria and melt viscosities; their partitioning between melt and fluid phase(s) upon decompression, 20 cooling and crystallisation of magmas in the ^ Earth's crust; and their final atmospheric release as volcanic 21 gases. The role of halogens in the genesis of hydrothermal systems and in the transport of ore-forming metals 22 is also reviewed, and we discuss our current understanding of atmospheric processing of volcanic halogens in 23 both the troposphere and stratosphere, and their consequent impacts. In spite of these recent advancements, 24 our current understanding of halogen geochemistry at active volcanoes is still far too fragmentary, and the 25 key questions that require answers from future research are summarised in our conclusions
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
Reactive solubility approach to the dissolution of halogens in basaltic melts
No full textPartitioning of halogens between gas and basaltic melts at 1200-1265°C and 10-2000
bar (Alletti, 2008) has been analyzed in detail by means of the CTSFG model (Moretti
and Ottonello, 2005) in order to: 1) evaluate redox conditions consistent with related
experimental information such as PH2 and S2−/S6+ ratio, 2) estimate the relative
abundance of H2O, CO2, KCl, NaCl and HCl of the gas phase, 3) investigate
the solubility mechanisms of chlorine and fluorine in (basaltic) melts. For chlorinebased
runs, it was found that for input [Na+K]/Cl atom ratios > 0.45 the proportion
of gaseous NaCl and KCl exceeds that of HCl. In terms of solubility mechanisms,
halogen chemical reactivity can be assessed in terms of dissolution into the melt as
chloride or fluoride ion, i.e, Cl− and F−. A complementary solubility mechanism can
be invoked to improve the precision and explain somehow unexpected features, such
as i) a P-independent background values of halogen solubility, and, for chlorine only,
ii) a XCl,melt-squareddependence shown by Cl dissolution. In this additional mechanism,
undissociated alkali-halogenides dissolve in the melt up to a solubility limit
which depends on structural conditions, i.e. on melt composition for the same T. Although
this could be a fascinating hypothesis, somehow recalling the concentration
limits of Henry’s law behavior for trace element dissolution into minerals, it is then
questioned whether this may reflect or not mixing of a molten salt-like component
with the silicate melt.
Partition coefficients derived from equilibrium constants of reactions involving Cl−
and F− show well the role of water vapor as stripping agent of chlorine. Therefore,
the more the CO2 in the system, the more the amount of chlorine getting dissolved
into the melt phase
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