Search results for " impianti"

Sampling of pairwise comparisons in decision-making

2019

Various decision-making techniques rely on pairwise comparisons (PCs) between the involved elements. Traditionally, PCs are provided by experts or relevant actors, and compiled into pairwise comparison matrices (PCMs). In highly complex problems, the number of elements to be compared may be very large. One of the issues limiting PC applicability to large-scale decision problems is the so-called curse of dimensionality, that is, many PCs need to be elicited from an actor, or built from a body of information. In general, when applied to a set of n elements to be compared, the number of PCs that have to be made is n(n−1)/2. When the information in the comparison matrix is complete, the priorit…

The Design of Effective Maintenance Outsourcing Contracts

2009

Recent developments in maintenance planning and management demonstrate that the establishment of optimized maintenance policies may drastically improve the performance and reduce the operating cost of facilities. However maintenance activities are typically outside of the core business of production facilities, hence enterprises often fail to catch the opportunities that may originate by properly optimized management strategies. A strategic maintenance management should hence encompass the possibility of outsourcing maintenance activities to ensure the necessary perfomance of production systems, while allowing enterprises to concentrate their resources on their core activities. In order to …

a diagnostic and prognostic system to enhance the operational readiness of mission critical systems

2009

Maintenance Planning For The Reliability Maximization In A Large System With Vagueness In The Reliability Values Of Some Components

2015

This paper tackles the problem to single out the maintenance actions to be executed on a production system during the planned stop of given length. In detail, from a reliability viewpoint the system is assimilated as a series-parallel multi-component system and the maintenance actions need to maximize the system reliability up to the next planned stop. Moreover, it is assumed that some components reliability values are affected by vagueness within a given range. To solve the considered problem, an exact dynamic programming algorithm suitable to quickly point out the maintenance scheduling is developed and, moreover, it is formulated a proper parameter able to express the robustness of the o…

The hydraulic behaviour of the prototype of on a ITER divertor cassette

2009

HEXCALIBER TEST SECTION. Thermo-mechanical analysis

2009

Thermal-hydraulic analysis on the cooling system of the target in the SPES plant

2012

Experimental data collection and modelling of dry deposition velocities for urban surfaces

2018

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 urban are…

FMECA Analyses of radiological over-exposure accident to patients in brachytherapy

2012

This paper presents safety analyses of accidental events which can involve patient during High Dose Rate brachytherapy treatment in over-exposures. The study has been performed by using the well-known techniques FMECA modified by Fuzzy logic theory. Moreover, fuzzy HEART methodology was employed in order to evaluate human error probabilities for each treatment stage. The obtained results, aimed to obtain a list of the deviations with a reasonable probability to produce significant adverse outcomes, provided some recommendations for procedures and safety equipments to reduce the occurrence of radiological over-exposure accidents.

A Training Experience of Operators with the AGN-201 “Costanza” Research Reactor of Palermo University

2011

The nuclear reactor AGN-201 named “Costanza”, installed at the Nuclear Engineering Section of the Department of Energy of the University of Palermo, is a “zero power” research reactor designed to be mainly used for education purposes as well as for research applications, such as activation analysis and irradiation tests, and last, but not the least, for radionuclide production to be used in nuclear medical applications. Due to its intrinsic safety and low margin of reactivity (less than 350 p.c.m.) so as to the absence of start-up and shut-down time limits, it represents a useful training tool for operators, too. This paper reports some of the activities carried out within the framework of …