1,721,305 research outputs found
Hierarchical approach to define travertine depositional systems: 3D conceptual morphological model and possible applications
No full text© 2019 Elsevier Ltd 3D modelling represents a powerful tool to characterize the geobody architecture of depositional systems. Several examples have been proposed in literature both for marine carbonates and siliciclastics rocks. For modelling, quantitative data related to orientation, shape and dimension are fundamental. Continental carbonates, however, are not considered yet, likely because they cover a large range of deposits such as speleothems, tufas, lacustrine carbonates and travertines. The interpretation of the depositional environments of the latter is still in fact debated by the scientific community. However, the interest in continental carbonates and especially travertines increased over the last decades due to the discovery of supergiant unconventional reservoirs in the Southern Atlantic (i.e. the so-called “Pre-salt play”). Aim of this paper is to present an innovative workflow to investigate and describe continental carbonates as geobodies based on a hierarchical approach applied to three large scale travertine settings, i.e. Terme di San Giovanni (Italy), Pamukkale (Turkey) and the Lapis Tiburtinus travertines (Italy). Travertine depo-systems are divided in three different depo-zones, namely proximal, intermediate and distal, that are characterized by different depo-elements, depo-shapes and depo-facies. Finally, a 3D morphological model is created based on numerical and vector approaches and interpolation of both. The model can be applied to seismic data of Brazilian and Angolan Pre-salt, highlighting the similarities between these systems and for the first time the scale independence of these depositional system, representing an important advantage in their interpretation. The 3D model and the approach proposed facilitates seismic interpretation, allowing to define and characterize geometries of inaccessible geological contexts.sponsorship: We are grateful to TOTAL S.A., Royal Dutch SHELL plc. and Petroleo Brasileiro S.A-PETROBRAS for funding the TraRAS project. Many thanks to Pacifici (Fratelli Dandini), Querciolaie (Francesca, Aurelio and Roberto) and Poggi (Maurizio and Valentino) quarries for all the assistance provided in the field. Special thanks give also to M. Cihat Alcicek, the editor Marco Brandano and the anonymous reviewer for handling our manuscript and for the very constructive comments. (TOTAL S.A., Royal Dutch SHELL plc., Petroleo Brasileiro S.A-PETROBRAS)status: Publishe
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Geogenic CO2 flux calculations from the Late Pleistocene Tivoli travertines (Acque Albule Basin, Tivoli, Central Italy)
No full textThe Lapis Tiburtinus travertine of the Acque Albule Basin (Tivoli, Central Italy) is a well-known travertine deposit composed by 10 units separated by unconformity surfaces. This travertine deposition is related to CO2 degassing of thermal waters circulating in deep carbonate-sulphate reservoirs. Since for each mole of calcite precipitated by groundwater, one mole of CO2 is degassing to the atmosphere, the volumes of travertine deposits can be used as an indirect proxy of the amount of CO2 degassed during travertine deposition. In the present work the volumes of the different travertine units and the cumulative amount of CO2 degassed per depositional unit (FCO2, which range between 1.56×108 mol a-1 to 5.93×108 mol a-1) have been computed. Furthermore, the fluxes of carbon dioxide per unit area (φCO2) were computed and compared to the δ18O curve and pollen data. The computed CO2 fluxes, range between 7.11×105 mol a-1 km-2 and 2.70×106 mol a-1 km-2. These values are minimum estimations of the deep CO2 degassing processes because of dissolution and erosion processes and possible CO2 loss from thermal water before their emergence at springs as well as because only the exposed travertine succession was used as proxy for the entire succession. The comparison of the CO2 flux data with the δ18O curve and pollen data shows that smaller variations in carbon dioxide flux are related to changes in climatic conditions, while greater variations are probably caused by the increase of the deep CO2 degassing process of the Acque Albule hydrothermal system, which is, in turn, relate to the activity of Colli Albani volcanic system
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