Search results for "SISTEMI"

Risk Assessment of Fuel Quantity Indicator Replacement in ATR72 Aircraft

2015

Aircraft maintenance activities are rife with opportunities for error. The concurrent in-flight failure of all of the engines of a non-scheduled airline flight and the following list of human lives highlight one of these opportunities. As commonly recognized among flight operators, each flight safety agency follows the criteria of the International Civil Aviation Organization Annex 16 in which all the evidences of the technical investigation pave the way for avoiding future flight accidents or incidents. On the other hand, when the Italian penal procedure code was applied for the Tuninter aircraft ATR 72 (identification code TS-LBB) crash at issue on 6 August 2005 near Palermo (Italy), the…

Benchmarking of airports service quality by a new fuzzy MCDM approach

2015

Recent approaches to the service quality evaluation problem are focused on the employment of multi-criteria decisionmaking (MCDM) procedures, since processes related to service quality evaluation presentmeaningful communality elements to MCDM ones. Based on such assumption, in the present paper a new fuzzy MCDMapproach is developed tocomparatively evaluate passenger service quality of the international airports inSicily (Italy). In particular, by incorporating the respondents confidence level and degree of optimism on fuzzy assessments, quality scores of main airport service criteria are estimated, whereas ELECTRE multi criteria decision support methodis proposed to point out theservices qu…

Considerazioni sull’approvvigionamento e smaltimento idrico dell’area centro-occidentale della Collina dei Templi di Agrigento in età classica

2020

A partire dalle recenti indagini dell’Università di Palermo nell’area tra i Templi di Zeus e di Eracle ad Agrigento, e dalla revisione condotta da Giovanni Luca Furcas dei sistemi idrici akragantini, si propongono alcune considerazioni su un importante aspetto della vita dei complessi sacri, ancora non adeguatamente approfondito. In particolare si cercherà di cogliere il legame tra l’infrastrutturazione idrica e lo sviluppo diacronico dei santuari nella porzione sud-occidentale della città. The paper examines the water supply and disposal in the central-western part of the Collina dei Templi at Agrigento. Starting from the current investigations by the team of the University of Palermo in t…

THE CAUSAL ROOTS OF INTEGRATION AND THE UNITY OF CONSCIOUSNESS

2016

A fundamental feature of consciousness is unity. The problem is whether unity is compatible both with the physical underpinnings of conscious experience and with the fabric of the physical world in general.

On the Finite Element Simulation of Secondary Operations on Metallic Foams

2007

Metallic foams have been recently introduced also as industrial materials due to their well known advantages. In fact, their low mass in conjunction with the good thermal and mechanical properties push toward an extensive diffusion in manufacturing industry. In the study here addressed, a very accurate investigation concerning the latter two aspects has been carried out. In fact, a secondary manufacturing process, i.e. the foam bending, has been taken into account. Anyway, all the knowledge derived for sheet metal bending is not directly applicable to the foams. A finite element code has been utilized for modeling the foam behavior during the bending processes and an accurate material rheol…

Characterization of friction stir consolidated recycled billet by uniaxial compression tests with miniaturized cylindrical specimen

2023

Abstract. Friction stir consolidation (FSC) is a solid-state recycling method that directly converts machining scraps into semifinished billets. This process has been proven to be a more energy efficient and environmentally friendly technique compared to remelting based conventional recycling methods. During FSC, machining chips are transformed into a solid billet by the stirring action and friction heat of the rotating tool. Due to process mechanics, especially temperature gradient and strain rate, billets have shown different hardness values and grain size distribution across their sections. Therefore, in this research, miniaturized upsetting samples are extracted from the FSC billet. The…

Fabrication of Billet from Aluminum Alloys AA 2011-T3/7075 Chips through Friction Stir Consolidation

2022

Recently evolving Solid-State Recycling (SSR) techniques have shown promising features to recycle metals scraps more efficiently compared to remelting-based approaches. Among these SSR methods, Friction Stir Consolidation (FSC) has been successfully tested to transform metals chips directly into semi or final solid products. Therefore, researchers explored FSC critical process parameters and their subsequent effects on quality in terms of the mechanical and metallurgical properties of the billet. All the previous studies of FSC were limited to developing billet of mono materials. Therefore, in this research, an attempt was made to go beyond the idea of recycling; in fact, a billet of two di…

Friction based solid state welding techniques for transportation industry applications

2014

Life Cycle Assessment of aluminum alloys chips recycling through single and multi-step Friction Stir Consolidation processes

2023

Manufacturing scientists have to find new processes enabling energy and resource efficient circular economy strategies. Solid state recycling processes have proved to be environmentally friendly alternatives to recycle aluminum alloys process scraps like chips. In this paper the environmental characterization of a solid state recycling process named Friction Stir Consolidation (FSC) is presented. A full Life Cycle Assessment (LCA) comparative analysis is developed: the environmental performance of new and different variants of FSC processes and remelting based routes are quantified and compared to one another. Also, different scenarios are analysed to provide guidelines for the correct impl…

Influence of Joint Geometry on Micro and Macro Mechanical Properties of Friction Stir Spot Welded Joints

2014

AbstractSpot welding can be considered a very common joining technique in automotive and transportation industries as it permits to obtain effective lap-joints with short process times and what is more it is easily developed through robots and automated systems. Recently, Friction Stir Spot Welding (FSSW) has been proposed as a natural evolution of the already known Friction Stir Welding (FSW) process, allowing to obtain sound spot joints that do not suffer from the insurgence of typical welding defects due to the melting of the base material. Similarly to FSW, both geometrical and technological parameters must be considered as they affect the material flow and the heat flux generated durin…