1,720,959 research outputs found
Sedimentation at River Mouths bounded by Coastal Structures: A Case Study along the Emilia-Romagna Coastline, Italy
Full text linkBeach retreat in the Emilia-Romagna coast, facing the north Adriatic Sea, is well-known since decades and several factors are behind this phenomenon: a scarcity of natural sediment supply by rivers, natural and anthropogenic subsidence, and a strong urbanization of the coastal zone. Several bedload measurement campaigns in one representative river of the Ravenna province (Savio River) have been carried out since 2017. At the same time, seasonal surveys of bathymetry were undertaken at the river outlet to correlate changes in sedimentation with river input. The river mouth is constrained by artificial embankments that possibly funnel out sediment offshore during river floods. However, monitoring of bedload transport correlated with bathymetric changes between July 2017 and November 2018 still found a positive budget of almost 5000 cubic meters. Local authorities in Ravenna are planning to dredge 20000 cubic metres from the river mouth to supply small nourishments outside the studied coastal cell. According to the measurements of bathy-metric changes, the Savio mouth will need almost six years to recover, assuming the occurrence of a particularly efficient rate of sediment transport, like the one observed in the monitored period. Notably, the analysed period included a very large river flood that could overshadow the modal sediment transport operated by the river. Furthermore, with deepening of the mouth, the two villages adjacent to the outlet are likely to become more exposed to sea flooding, due to the propagation of surges inside the river mouth. The paper concludes that dredging activities should be reconsidered in view of the precarious equilibrium of the system
Bedload transport and dune bedforms characteristics in sand-bed rivers supplying a retreating beach of the northern Adriatic Sea (Italy)
No full textStudy Region: The coast of the Emilia-Romagna Region in northern Italy consists of about 210 km of sandy beaches that have been attracting tourists for decades. Since the 1980s, erosion processes resulted in a remarkable beach retreat, notwithstanding the construction of several protections works. Study Focus: In 2005–2006 and 2017–2020, 30 floods of two small rivers feeding the beaches of Ravenna, Fiumi Uniti and Savio, were monitored and bedload was measured with a Helly-Smith sampler. Riverbed bathymetric surveys were carried out after some selected floods to investigate the occurrence and geometry of alluvial bedforms. The dune migration method was also used to calculate bedload. Results provided by this method are very encouraging. New Hydrological insights for the Region: To the authors knowledge, this field investigation on the bedload transport of small coastal rivers is the first one of this kind in the Adriatic and provides the regional land managers with a useful tool to predict the bedload yield for future scientifically based interventions, and hopefully successful, beach protection works. The bedload data indicate a higher variability of bedload for discharges lower than bankfull flow, whereas a stronger control of discharge is evident for larger floods. Though the bedload of the study rivers proved to be higher than in the largest river of the Region, it resulted rather low and witnesses sediment supply-limited conditions
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
Bedload transport processes in a coastal sand-bed river: the study case of Fiumi Uniti river in the northern Adriatic
No full textOver the last decades, most of the Emilia-Romagna (Italy) beaches have been affected by marked erosion that is still progressing, which is primarily due to the reduction of sediment supply by the local rivers. In addition to larger fluvial systems, the role of small rivers has been recognized as important in contributing to both beach stability and changes. Bedload measurements were carried out by previous authors in 2005–2006 but, in order to widen the data set of river sediment supply for the whole region, a new bedload measurement campaign was performed in 2017 on the Fiumi Uniti River, a typical example of a small river system whose sediment supply variations substantially influence the stability of the beaches adjoining its mouth. Marked changes were observed in the bedload transport rates and bed material grain size between the two sampling campaigns of 2005/2006 and 2017. The threshold conditions for bed particle entrainment are analysed by means of the Shields classical criterion and other approaches. The results indicate that all these criteria are unable to predict the actual value, except for Carling and Bagnold criteria. This result has large implications in the assessment of bedload yield in sand-bed rivers
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
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