1,720,956 research outputs found
Is it possible to use different data types and scales to reduce flow and transport uncertainty in natural heterogeneous formations? The experimental setup of the Settolo aquifer (Italy)
No full textThe uncertainty characterizing the description of hydraulic properties of aquifers, together with those implied in the process modeling and measurement errors, can be successfully dealt with by stochastic approaches, which allow the interpretation and the prediction of flow and transport processes in natural heterogeneous formations. The practical application of these approaches still encounters many difficulties, mainly due to the need for a detailed hydrogeological characterization of the site and to the unsuitability of the models, sometimes related to simplistic schematizations when describing in random terms the aquifer and its processes. The need to describe the spatial joint probability distribution of the hydraulic properties at different scales demands a large amount of data, to be obtained by several in situ and laboratory measurements. Moreover, modeling of these processes is often limited by the hypotheses of statistical homogeneity of the flow field and ergodicity of the dispersive process. These approaches are not suitable for the cases of practical interest, where the finite domain is characterized by irregular shapes and the flow field can be highly non-homogeneous, due to the influence of the boundary conditions, the presence of localized pumpings or inflows, or the lack of spatial stationarity of the hydraulic conductivity. Such circumstances emerge clearly in the real case of Settolo, an alluvial phreatic aquifer in a piedmont area of Northeastern Italy, where the effects related to the variability of the geological structures crossed by paleo-riverbeds and characterized by different facies, to the interactions between watercourses and the aquifer, to the recharge linked to the precipitation, and to the correct interpretation of concentration measurements of solutes must be challenged for an effective protection and/or a sustainable exploitation of the water resources. For these reasons, a careful site characterization is in progress, with a number of different measurements and scales involved. A surface geophysical survey has been carried out to investigate the thickness of the aquifer; water levels in the Piave river are being monitored for a detailed characterization of the boundary conditions; a network of piezometric wells has been installed to monitor water table and for the development of incoming pumping tests; and the geophysical interpretation of tracer tests (ERT) and breakthrough curve measurements are being planned for a local scale characterization of transport. We present here the data recorded at Settolo in the first six months of monitoring activities and the preliminary modeling results. The ultimate objective of the research is to suggest an integrated approach developed by means of models operating at different scales to seek a solution to the overall problem of flow and transport in natural heterogeneous formations
Is it possible to use different data types and scales to reduce flow and transport uncertainty in natural heterogeneous formations? The experimental setup of the Settolo aquifer (Italy)
No full textIdentifying Pipeline Leak Positions Potentially Connected To Soil Deformations Through SAR Data Analysis
No full textTransmission mains (TMs) and water distribution systems (WDS) are, among the others, fundamental networks on which society relies on. Age, pipeline materials, and internal and external stresses are just few of the numerous factors that undermine the efficiency of these infrastructures and potentially reduce performance and functionality, leading to leakages or causing dangerous conditions in the surrounding environment, such as flooding or disruption. Accurate condition assessment, with suitable monitoring techniques, allows for proper management and maintenance throughout the infrastructures' lifetime. Starting from the hypothesis that leakages could be related to soil deformation, this study evaluated the opportunities offered by the differential interferometric synthetic aperture radar (DInSAR) method in identifying soil deformations in nonurban areas potentially related to leak positions along TMs. Satellite images were analyzed to derive millimetric evolution of slow deformation processes over large surfaces and a long time frame. To test the capability of the proposed method and its operability as a monitoring tool, data acquired between 2014 and 2019 by Sentinel-1 satellites, were processed to investigate two transmission pipelines located in two areas of Italy (Veneto and Toscana regions). An analysis of historical damages in the hydraulic network and soil deformations obtained by synthetic aperture radar (SAR) data examination along the pipeline path suggests how and in which conditions potential relationships between leakages along pipeline and deformations of the ground surface can be defined
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
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