1,720,983 research outputs found
Benthic foraminiferal proxies of environmental changes during the pre-Messinian salinity crisis of the Sinis Basin (W Sardinia, Mediterranean Sea)
Full text linkThe Messinian succession cropping out in a marginal basin of the Mediterranean Sea (Sinis Basin, W Sardinia) was studied in its benthic foraminiferal content in order to investigate the main palaeoenvironmental changes occurring. A shallowing upward depositional trend, from an upper bathyal-circalittoral environment to a coastal lagoon, was recognized during the pre-Messinian Salinity Crisis. In the lower part of the analyzed succession (Capo San Marco Formation), upper bathyal-circalittoral conditions are suggested by species with a wide depth-range, such as Cibicidoides pseudoungerianus, Melonis pompilioides, Oridorsalis umbonatus, bolivinids and buliminids. In the middle part of this formation, the progressively shallowing environment is indicated by the low abundance of planktonics coupled with the upward increase of shallow-water epiphytic species (Lobatula lobatula, Elphidium crispum, E. macellum, Ammonia beccarii, Hanzawaia boueana). The progressive marine restriction led to the development of hypohaline conditions typical of lagoonal environments as suggested by Ammonia tepida and oligotypic macrofaunas. The succession stops with the deposition of laminated limestones barren in fossils (Sinis Laminated Limestone Formation). A mixed siliciclastic‐carbonate platform (Torre del Sevo Formation), characterized by fluvial deposits intercalated in the marine succession, developed as suggested by benthic foraminifera, ostracods, very rare planktonic species and macrofaunas. Sinis Laminated Limestone Formation and Torre del Sevo Formation constituted part of the Terminal Carbonate Complex, strongly eroded by the Messinian Erosional Surface (MES) at its top. The palaeoecological conditions in the Sinis Basin were intermittently suitable for sustaining full-marine biota, indicating that this marginal basin was not constantly desiccated during the pre-Messinian salinity crisis
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
Benthic foraminifera and trace elements distribution: a case study from the heavily polluted Lagoon of Venice (Italy)
No full textA novel technique to mitigate the effect of gapping on the uplift capacity of offshore shallow foundations
Full text linkA flexible mat was provided around the periphery of skirted shallow foundations - a so-called 'gap arrester' - to assess the potential to mitigate the effect of gapping on uplift capacity. Results are presented from a series of drum centrifuge tests on skirted foundations with an intact skirt/soil interface, a gapped skirt/soil interface, and a gapped interface with gap arrester, subjected to undrained and sustained uplift. The results are promising, showing that the provision of an effective gap arrester preserves suction to larger foundation displacements and reduces the rate of displacement under sustained uplift, compared with the case of a gapped interface without arrester.</p
Sustainable mobility and user preferences by crowdsourcing data: the Open Agora project
No full textOne application of network optimization is the study of the policies able to change people habits in transportation mode selection. The main strategy for achieving this objective is to develop a model describing the preferences of the people by considering the characteristics of the transportation modes (such as cost, travel duration) and then to develop policies in order to improve the characteristics of the target transportation mode. These models are called utility models and have a long story. Nevertheless, the data needed for their fitting are difficult to get. One of the main issues in this case is how to collect the data and how to tune a model that can be easily scaled and adapted to different settings. In this paper, we describe the results achieved during the Open Agora project where the utility model is tined with crowdsourcing data coming from mobile phone applications and collected indirectly by the users
Benthic foraminifera and trace elements distribution: a case study from the Venice Lagoon (Italy)
No full textA numerical study of the vertical bearing capacity of skirted foundations
No full textFinite element analysis is used to investigate the vertical bearing capacity of circular skirted foundations considering the effect of embedment ratio, foundation-soil interface roughness and soil strength heterogeneity. The effect of idealising a skirted foundation as a solid rigid plug and idealising geometry to conditions of plane strain are also addressed through comparison of bearing capacity factors and kinematic mechanisms accompanying failure. A closed-form expression is presented that enables prediction of bearing capacity factors for circular skirted foundations over a practical range of embedment ratio, skirt-soil interface roughness and soil strength heterogeneity, to within ±2.5% of the finite element calculations.</p
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
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