1,721,030 research outputs found
Storie ad arte: racconti che diventano immagini, immagini che diventano racconti
No full textLe forme della narrazione possono essere le più diverse: non solo parole, ma anche gesti e simboli, arte e poesia.
I linguaggi dell’arte costituiscono da un punto di vista pedagogico un’area tematica importante che arricchisce ed amplia l’universo narrativo umano, in quanto permette di veicolare espressioni, sensazioni, significati e vissuti emotivi e, quindi, consente di imparare a “pensare coi propri sensi”.
Nell’epoca della comunicazione digitale non si può prescindere dalla considerazione dei diversi medium attraverso cui i racconti sono prodotti, definendo nuove forme di narrazione, inedite costruzioni di significati, nuovi linguaggi che si contaminano a vicenda, ripercorrendo altresì le origini, attraverso l’utilizzo del segno.
Il paper intende riportare un’esperienza laboratoriale il cui obiettivo principale è stato quello di fornire alle partecipanti un’esperienza di apprendimento e di espressione estetica, utilizzando tracce (da quella poetica a quella grafica a quella pittorica).
The forms of narrative can be very different: not just words, but also gestures and symbols, art and poetry. From a pedagogical point of view, the languages of art represent an important issue, enriching and expanding human narrative universe, as they allow to convey expressions, feelings, emotional meanings and experiences and, consequently, lead to “think with our own senses”.
In the age of digital communication, we cannot consider independently the different mediums through which tales are produced, defining new forms of storytelling, original constructions of meanings, new languages that mingle together, retracing the origins, through the use of the sign.
This paper aims to bring a workshop experience, whose main objective was to provide the participants a learning experience and an aesthetic expression, using different traces (from poetry to graphics or painting)
Effect of different system parameters on the design of the EU DEMO Vacuum Vessel Pressure Suppression System
Full text linkThe Vacuum Vessel Pressure Suppression System (VVPSS) is the safety system devoted to the mitigation of in-vessel Loss-Of-Coolant Accidents, which are considered among the Design-Basis Accidents for tokamak fusion reactors. The EUROfusion Consortium is performing the design of this system, as part of the conceptual design phase of the EU DEMO fusion reactor, including in the process its integration in the plant.
This work reports the first parametric calculations carried out to evaluate the VVPSS response to a postulated double-ended guillotine rupture of a Breeding Blanket coolant feeder. The aim of the study is to characterize the role that key parameters play on the multiple systems involved in such an accidental event. Assessments scanned a broad range of design variables, some closely related to the suppression system itself, and others dependent on Primary Heat Transfer System features. The parameter space is mapped identifying the regions where the accident consequences are fully mitigated, in terms of peak pressure in the Vacuum Vessel (VV) and equilibrium pressure of both VV and VVPSS, providing a design tool to rapidly adapt the VVPSS to the evolving plant design
Activated corrosion product contamination assessments of DEMO WCLL breeding blanket primary heat transport system
Full text linkIn water-cooled fusion reactors, the assessment of the primary system contamination is essential for waste management, machine availability, occupational radiation exposure, and radiological hazard determination. The primary cooling water is not only directly activated by the intense neutron field but is a contamination vector for a significant variety of gamma emitters with short to long decay half-lives. Corrosion products can be activated in those regions under neutron flux of the primary circuit and then released in the cooling water.
In the EU-DEMO fusion power plant equipped with the Water-Cooled Lithium Lead Breeding Blanket (WCLL-BB) concept, the primary coolant undergoes intense neutron fields in the first wall and the breeding zone regions of the blanket. Activated Corrosion Products (ACPs) are then formed, released into the water, transported in the cooling loop and finally deposited onto the ex -vessel surfaces of the Primary Heat Transport System (PHTS), where working personnel are susceptible to being radiologically exposed.
This work addresses the complete assessment of ACPs in the WCLL-BB PHTS of EU-DEMO. The simultaneous and multi-physical processes behind the ACP formation are tackled using the OSCAR-Fusion code, a comprehensive tool developed by the CEA (France) to assess contamination in fusion nuclear reactors. The whole system is modelled with zero-dimensional nodes with assigned geometrical, thermal-hydraulics, material and chemical parameters. Activation reaction rates integrated over the whole spectrum and calculated with MCNP are given to those regions exposed to the neutron flux. Results are provided in terms of mass and activity inventories of ACPs as deposit and inner oxide layers of components (pipes, heat exchangers, pumps...), ions in solution, particles in suspension, and filters and resins trapping.
Mobilizable inventories such as ions, particles and deposits are important source terms in accidental scenario evolutions, while the whole activity inventory constitutes the main long-term gamma emitting source for dose rate maps determination in the tokamak building rooms housing the main PHTS equipment
Preliminary CAD implementation of EU-DEMO primary heat transfer systems for HCPB breeding blanket option
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Analysis of a full-scale integral test in PERSEO facility by using TRACE code
Full text linkOver the last decades a lot of experimental researches have been done to increase the reliability of passive decay heat removal systems implementing in-pool immersed heat exchanger. In this framework, a domestic research program on innovative safety systems was carried out leading the design and the development of the PERSEO facility at the SIET laboratories. The configuration of the system consists of an heat exchanger contained in a small pool which is connected both at the bottom and at the top to a large water reservoir pool. Within the frame of a national research program funded by the Italian minister of economic development, the DEIM department of the University of Palermo in cooperation with ENEA has developed a computational model of the PERSEO facility in order to simulate its behaviour during an integrated test. The analysis here presented has been performed by using the best-estimate TRACE code and - in order to highlight the capabilities and limits of the TRACE model in reproducing qualitatively and quantitatively the experimental trends - the main results have been compared with the experimental data. The comparison shows that the model is able to predict the overall behaviour of the plant during the meaningful phases of the transient analysed. Nevertheless, some improvements in the modelling of certain components in which take place complex three-dimensional phenomena are suggested in order to reduce some discrepancies observed between code results and test measurements
On the thermal dynamic behaviour of the helium-cooled DEMO fusion reactor
Full text linkThe EU-DEMO conceptual design is being conducted among research institutions and universities from 26 countries of European Union, Switzerland and Ukraine. Its mission is to realise electricity from nuclear fusion reaction by 2050. As DEMO has been conceived to deliver net electricity to the grid, the choice of the Breeding Blanket (BB) coolant plays a pivotal role in the reactor design having a strong influence on plant operation, safety and maintenance. In particular, due to the pulsed nature of the heat source, the Primary Heat Transfer System (PHTS) becomes a very important actor of the Balance of Plant (BoP) together with the Power Conversion System (PCS). Moreover, aiming to mitigate the potential negative impact of plasma pulsing on BoP equipment, for the DEMO plant is also being investigated a "heat transfer chain" option which envisages an Intermediate Heat Transfer System (IHTS) equipped with an Energy Storage System (ESS) between PHTS and PCS. Within this framework, a preliminary study has been carried out to analyse the thermal dynamic behaviour of the IHTS system for the Helium-Cooled Pebble Bed (HCPB) BB concept during pulse/dwell transition which should be still considered as the normal operating mode of a fusion power plant. Starting from preliminary thermal-hydraulic calculations made in order to size the main BoP components, the global performances of DEMO BoP have been quantitatively assessed focusing the attention on the attitude of the whole IHTS to smooth the sudden power variations which come from the plasma. The paper describes criteria and rationale followed to develop a numerical model which manages to simulate simple transient scenarios of DEMO BoP. Results of numerical simulations are presented and critically discussed in order to point out the main issues that DEMO BoP has to overcome to achieve a viable electricity power output
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
Analysis of Coolant Purification Strategies for Tritium Control in DEMO Water Primary Coolant
Full text linkA major objective of the European fusion program is the design of the DEMOnstration power plant named DEMO. Up to now, most fusion experiments have been dedicated to a plasma physics investigation while, in DEMO-oriented activities, large attention is devoted also to other systems necessary to produce tritium and to convert the fusion power to electricity. The blanket region, responsible for tritium breeding, is characterized by high tritium concentrations, high temperature, and large heat transfer metallic surfaces in which tritium can permeate. Therefore, the problem of tritium permeation and the resulting tritium content in the primary coolant are of great relevance for DEMO. For the pre-conceptual design of the Water-Cooled Lead–Lithium variant, the tritium permeation rate from blanket into coolant was assessed and possible mitigation strategies were suggested. Starting from a review of the CANDU tritium experience, a preliminary assessment of the maximum tritium concentration target in the DEMO primary coolant was performed and different strategies (off-line, on-line, and hybrid) for the water coolant purification system coupled with the DEMO operating scenario were analyzed. The intent is to identify suitable solutions to reduce the tritium concentration inside the water coolant, having in mind the complexity of a water detritiation process
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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