1,721,021 research outputs found
Parametric analysis of the ITER TF fast discharge using the 4C code
No full textThe recently developed and validated 4C code is used to analyse the fast discharge of an ITER TF coil, including the cooling circuits of winding and casing, and the quench venting system. The analysis shows that a quench can be initiated by the fast discharge, depending on the value of the thermal resistance of the conductor turn insulation. Eddy currents heat the structures and these transfer the heat especially to the side pancakes, where the quench is initiated. The hot spot temperature remains below ~37 K in the winding and 55 K in the structures. The peak pressurization in the winding remains below 8.5 MP
Stability analysis of the ITER CS coil conductors
No full textThe stability analysis of the International Thermonuclear Experimental Reactor (ITER) Central Solenoid (CS) coil Nb3Sn conductor is performed following a similar approach to that recently used for the ITER Toroidal Field and Poloidal Field conductors. The most critical conductors in the winding pack, as well as the most critical (minimum temperature margin) location along them, are identified by the application of the Vincenta code, which also provides the initial and boundary conditions in the reference case. The Mithrandir code is then applied to these conductors, using a much finer grid than affordable in the Vincenta analysis, in order to capture the details of normal zone initiation and possible recovery to SC state when different square wave disturbances of length L in the range [0.01 m, 7 m] and duration τ in the range [1 ms, 100 ms] are applied to the superconducting cable. The computed minimum quench energy is shown to be typically above (in one case borderline to) the expected disturbance. The sensitivity to parametric variations of the heat transfer coefficient between strands and helium is significant for some disturbances. The inclusion of an external circuit in the model, providing selfconsistent boundary conditions, does not influence the results
CSNI validation matrix for the assessment of thermal-hydraulic codes for PWR LOCA and Transients
No full textAs Italian representative inside the thermal-hydraulic task group of Organization for Economic Cooperation and Development (OECD) / Nuclear Energy Agency (NEA) / Committee on the Safety of Nuclear Installations (CSNI), the current author contributed to a preliminary activity which ended up in an OECD publication. The framework of the activity is assessment and validation of system thermal-hydraulic codes.
Preliminary steps were taken to fix the requirements for the validation. Importance was given to the experimental data and to the scaling processes. The document evolved in about five years to the form a pillar document in the area of nuclear thermalhydraulics. Coauthors were top level researches and specialists working in the area at the time
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
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