1,721,022 research outputs found
The geostatistical approach for the restoring of pollutant release applied to experimental column data and Monte Carlo numerical tests.
No full textExcavations on the Acropolis of Mishrifeh, Operation J. A New Early Bronze Age III – Iron Age III Sequence for Central Inner Syria. Part 2: The Pottery
No full textA case study of management and disposal of tenorms: Radiological risk estimation by tsd dose and resrad-onsite
Full text linkNaturally Occurring Radioactive Materials (NORMs) and Technologically Enhanced NORMs (TENORMs) are among the principal sources of radiation exposure for humans and for the environment. Therefore, the assessment of the impact of NORMs and TENORMs waste on human health is a key issue for their management and for acceptance of disposal sites. The radiological doses to workers and public due to TENORMs disposal depend on the waste inventory, on the usage of the site during operational activities and post closure phase and on the presence of dwelling areas in the vicinity of the disposal site. In the present study it is presented a methodology to preliminary assess the feasibility of a disposal of TENORMs, mainly constituted by phosphate sludges, originated from phosphoric acid industry activities. The hypothetical case study here presented is inspired by a real case study. Different possible scenarios have been considered. The potential doses to workers and to the public on-site have been estimated by the use of the TSD Dose and the RESRAD on-site codes both during the production life cycle of the site and once it ended. Sensitivity analyses were conducted to evaluate the impact of some key parameters, such the coverage thickness and wind velocity, on potential risk for workers and public
About the dependence of breakthrough curves on flow direction in column experiments of transport across a sharp interface separating different porous materials
Full text linkConservative transport experiments with layered porous materials (coarse-grained vs. fine-grained) were performed through experimental cylindrical columns to assess the possible occurrence of interface processes at the discontinuity between media with different hydrodynamic and hydrodispersive properties, as proposed by some authors in the past based on modelling and experimental results. The outcomes of the present work show that, under certain conditions, the breakthrough curves (BTCs) obtained for flow through the coarse-grained and then through the fine-grained media (CtF) or vice versa (FtC) can differ. More specifically, an asymmetric behaviour is observed for cases when the ratio between the column and grain diameters is small. Moreover, the discrepancies between CtF and FtC BTCs are enhanced for low flow rates and low quantity of injected solute
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
Study of caesium adsorption onto alluvial sediments from the Italian Po Plain
Full text linkThe study investigates the adsorption processes of caesium onto alluvial sediments from the Po Plain (northern Italy). Understanding these adsorption processes is crucial for assessing the safety of low- and intermediate-level radioactive waste repositories, including the proposed Italian repository. Adsorption kinetics and equilibrium experiments on sandy samples were conducted with the aim of evaluating how even small differences in clay content and mineralogy can affect kinetics and equilibrium adsorption behaviour. The obtained data were compared with literature studies and confirmed the significant affinity of caesium for sandy sediments, even for a mud content of less than 5%. Kinetics analysis revealed that a pseudo- second-order model best described the process, suggesting two-site occupancy adsorption kinetics attributed to the presence of illite and characterised by various different sites for caesium adsorption. Samples with higher clay and micaceous miner- als content, cation exchange capacity and specific surface area exhibit faster kinetics and higher affinity for caesium. The study shows a significant variation in partition coefficient values, ranging from 57 to 750 mg L −1 . This finding emphasises the importance of sediment composition in caesium adsorption, which is crucial for developing accurate environmental protection and safety assessment models
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