Search results for "IMPIANTI"

Parametric thermal analysis for the optimization of Double Walled Tubes layout in the Water Cooled Lithium Lead inboard blanket of DEMO fusion reactor

2019

Abstract Within the roadmap that will lead to the nuclear fusion exploitation for electric energy generation, the construction of a DEMOnstration (DEMO) reactor is, probably, the most important milestone to be reached since it will demonstrate the technological feasibility and economic competitiveness of an industrial-scale nuclear fusion reactor. In order to reach this goal, several European universities and research centres have joined their efforts in the EUROfusion action, funded by HORIZON 2020 UE programme. Within the framework of EUROfusion research activities, ENEA and University of Palermo are involved in the design of the Water-Cooled Lithium Lead Breeding Blanket (WCLL BB), that …

Inoculum of Indigenous Microalgae/Activated Sludge for Optimal Treatment of Municipal Wastewaters and Biochemical Composition of Residual Biomass for…

2022

In this work, municipal wastewater was treated with microalgal/activated sludge consortia. We aimed at obtaining a positive interaction between the microalgae and the heterotrophic bacteria and identifying the best combination for bioremediation purposes. A strain of Chlorella sp CW2 employed in this work was isolated from AS and molecularly characterised in this work for the first time. This strain and another previously isolated strain (Chlorella sp Pozzillo) were inoculated alone and in combination with AS in different ratios in wastewaters. Microalgae/activated sludge growth curves were obtained by using a UV–vis spectrophotometer and a fluorimeter to distinguish the contribution of the…

Dry deposition models for radionuclides dispersed in air: a new approach for deposition velocity evaluation schema

2017

In the framework of a National Research Program funded by the Italian Minister of Economic Development, the Department of Energy, Information Engineering and Mathematical Models (DEIM) of Palermo University and ENEA Research Centre of Bologna, Italy is performing several research activities to study physical models and mathematical approaches aimed at investigating dry deposition mechanisms of radioactive pollutants. On the basis of such studies, a new approach to evaluate the dry deposition velocity for particles is proposed. Comparisons with literature experimental data show that the proposed dry deposition scheme allows to capture the main phenomena involved in the dry deposition process…

Experimental investigation of two-side heat transfer in spacer-filled channels

2020

Abstract In Membrane Distillation (MD), spacers support the membranes and promote mixing, thus reducing temperature polarization. Their efficient design requires a knowledge of the distribution of the local heat transfer coefficient h and of its dependence on Reynolds number, spacer geometry and flow-spacer relative orientation. In previous work, we applied Thermochromic Liquid Crystals (TLC) and digital image processing to the measurement of h distributions for different spacer configurations; data were used to validate CFD simulations and select turbulence models. For constructive reasons, the test section allowed only one-side heat transfer, while in most MD configurations (e.g. spiral-w…

Cold Leg LBLOCA uncertainty analysis using TRACE/DAKOTA coupling

2022

Abstract Safety analyses for nuclear power plants were carried out in the past using a conservative approach. With the increase of the phenomenological knowledge, through experimental data, and computational power, it became possible to adopt best estimate thermal- hydraulic system codes to perform deterministic safety analyses. However, some uncertainties are still present in the models, correlations, initial and boundary conditions, etc. Therefore, it is fundamental to quantify the uncertainty of calculation. This approach is called “Best Estimate Plus Uncertainty” (BEPU). Among the available uncertainty analysis methodologies, the probabilistic method to propagate input uncertainty is wi…

On the modelling of tritium transport phenomena at fluid-structure interfaces

2022

Abstract One of the main functions of the DEMO Breeding Blanket (BB) system is to ensure the tritium breeding inside the reactor. Tritium is a beta emitter radioactive isotope, subjected to several processes that determine its permeation across materials and its leakage towards the environment, posing potential safety issues in terms of radiological hazard. Thus, the evaluation of tritium inventories inside components and tritium losses towards the environment plays a key role in the fulfilment of the pertinent BB safety requirements. In this regard, a research activity has been carried out, in close cooperation between the University of Palermo and the Karlsruhe Institute of Technology, fo…

Dry deposition of particle on urban areas

2019

Abstract Dry deposition process is recognized as an important pathway among the removal processes of radioactive pollutants in atmosphere. There is not a unique and accepted theoretical description of involved dry deposition phenomena due to the complexity of the fluid-dynamic processes that influence the deposition flux, but also because there is a lack of experimental data covering all scenarios of interest. In this paper, that is the result of a National Research Program a research activity conducted by DEIM Department of the University of Palermo and ENEA and funded by the Italian Minister of Economic Development, a new schema for parameterization of particle dry deposition velocity on …

A Multistep Methodology for the Evaluation of Human Resources Using the Evidence Theory

2013

New relations between professional and work’s organizations introduced by computer applications, special vessel case study

2019

At present time the project of a naval vehicle, where with the word project we refer to all the process of design and manufacturing, especially when the vehicle offers special formal and performance characteristics, involves a number of operators that has been increasing considerably in recent decades, and this increased complexity can be correlated with dimensional and typological growth of many categories of ships. Simultaneously we are witnessing a complete new project approach, where the possibility given by the computer contribution to represent processes and results becomes crucial. The paper aims to investigate the consequences of this progress in the organization of the project and …

Supercritical water gasification of microalgae and their constituents in a continuous reactor

2016

The supercritical water gasification of Nannochloropsis gaditana microalgae has been studied in term of process development at 24 MPa and 663 °C. Gasification has been investigated using a 200 cm3 down flow reactor working continuously. The effect of microalgae slurry concentration, with or without alkali catalysts, was studied. Moreover, the role played by different constituents of microalgae on gasification was investigated. Particularly, gasification of amino acids, carbohydrates and model mixtures among them was studied. Nannochloropsis gaditana was successfully gasified up to 97.4 wt% as gasification efficiency and 86.0 wt% as carbon efficiency. The product gas is mainly composed of hy…