1,721,124 research outputs found
Melt Transport and Mantle Assimilation at Atlantis Massif (IODP Site U1309): Evidence from Chemical Profiles along Olivine Crystallographic Axes.
No full textHybrid origin of the Erro-Tobbio troctolites (Ligurian ophiolites, Italy): structural and geochemical evidence of multi-stage evolution
No full textElectron Backscatter Diffraction (EBSD) analysis through fast-spread lower oceanic crust of Wadi Gideah in the Oman ophiolite
No full textThe microstructural data presented here were obtained from a reference profile which we established along the lower oceanic crust of Wadi Gideah in the Oman ophiolite (Wadi Tayin Massif; e.g., Nicolas et al., 2000). The Oman ophiolite is widely regarded as the best-preserved analogue of fast-spread oceanic crust on land, and therefore provides an ideal natural laboratory for investigating accretion processes beneath fast-spreading mid-ocean ridges. Our data set contains 68 samples from the axial melt lens down to the mantle transition zone with an average spacing of 81 m between two samples. This extensive data set provides insights into mechanical processes during crustal accretion. The data focuses on the three major primary phases plagioclase, clinopyroxene and olivine. The latter shows significant serpentinization such that the former two provide a much better continuity along the crust. The varitextured and foliated gabbros reveal significantly finer grain sizes in plagioclase and clinopyroxene than the layered gabbros. The fabric strength quantified by the ODF J index of both phases is generally low in the upper 1500 meters and increases gradually down section with significant scattering below 3500 meters above the Moho. The lowermost 1000 meters reveal a decreasing fabric strength. Misorientation in plagioclase and clinopyroxene grains shows a similar trend whereas misorientation in olivine is generally stronger and more scattered along the crust. The BA index, quantifying the pole figure symmetry of plagioclase with 0 for a purely foliated and 1 for a purely lineated fabric, shows intermediate symmetries with a significant lineation in the upper 1500 m before it shifts towards nearly purely foliated symmetries between 3500 and 2700 meters above the Moho. Below 2700 meters, the lineation component increases down section copying the scattering of the ODF J index
From mantle peridotites to hybrid troctolites: Textural, structural and geochemical evolution during multi-stage melt-rock interaction history
No full text
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
Filtered EBSD dataset in slow spread oceanic gabbros, IODP Expedition 360
No full textThe dataset contains the electron backscattered diffraction (EBSD) filtered data acquired on samples collected on cores from IODP Hole U1473A. A suite of 102 samples in gabbroic lithologies was analyzed through 116 EBSD maps of variable area width, generally 1-2 cm², and 3-3.5 cm² in coarse-grained samples. The scanning resolution was chosen as a function of the average minimum grain size of each analyzed sample and varies from 2.5 µm to 30 µm (average resolution: 10 µm). Raw pixel data was filtered with the Channel 5 analysis suite from HKL Technology (Oxford Instruments) and consists in a noise reduction followed by a wild spikes extrapolation (level 6)
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
- …
