Search results for "SISTEMI"
showing 10 items of 2026 documents
Shear coefficient determination in linear friction welding of aluminum alloys
2015
In the present study, a combined experimental and numerical investigation on Linear Friction Welding (LFW) of AA2011-T3 aluminum alloy was carried out in order to find the temperature dependent shear coefficient to be used in a 3D numerical model of the process. Torque, oscillation frequency and pressure were acquired in order to calculate the shear stress at the interface. A numerical thermal model was used to calculate the temperature at the interface between the specimens starting from experimental temperatures acquired through a thermocouple embedded in the LFW specimens. Finally, the calculated shear coefficient was used to model the contact between the two specimens in a dedicated 3D,…
On the effectiveness of spif process to re-form end-of-life components as compared to conventional forming approach
2021
Manufacturing processes have a significant impact on global energy consumptions. The recovery of materials and functions for the implementation of the Circular Economy principle needs to be focused on either, by utilizing new techniques or the rethinking of old processes to rework End-of-Life (EoL) components. Previous researches have shown Single Point Incremental Forming (SPIF) process as a good alternative for sheet metal EoL components reuse by their reshaping. In this article, the authors aim to study the effectiveness of the SPIF processes by comparing its reshaping performance with other, more conventional forming processes. An initial Deep Drawing (DD) process was performed to imita…
Material Substitution for Automotive Applications: A Comparative Life Cycle Analysis
2012
Lightweight materials have become an important strategy in the automotive industry to enable vehicle weight reduction and reduce fuel consumption. However, when developing specific strategies, the overall benefits of any material should be analyzed throughout its life cycle to comprehend energy/environmental differences that arise during its processing and its final use. A key example is aluminum which despite having great potential in the use phase requires large amounts of energy to process. This paper provides a comparison between aluminum and steel utilizing a life-cycle approach. This approach reveals the importance of incorporating a recycling strategy to leverage aluminum’s low-weigh…
MODELLISTICA MATEMATICA E PIATTAFORME INFORMATICHE A SUPPORTO DELLA RICERCA AMBIENTALE
2021
La modellizzazione matematica è diventata ormai uno strumento essenziale nell’avanzamento delle conoscenze in qualsiasi campo della scienza, dall’econometria alla psicologia, dalla chimica all’epidemiologia, come vissuto di recente nella pandemia da SARS-coV-2. Anche quelle che erano una volta discipline “soft” come la biomedicina o l’ecologia possono ora usufruire di tecniche di rappresentazione ed esplicazione dei processi estremamente utili alla comprensione delle dinamiche in gioco. Questa evoluzione, dovuta in non piccola parte all’attuale disponibilità di abbondante potenza di calcolo elettronico a costi ridotti, non è però opera ed appannaggio soltanto della nostra generazione. Lo st…
Die Regelung der DNA-Untersuchung im italienischen Gesetz v. 30.6.2009 – Nr. 85 und in der Strafprozessordnung Italiens
2013
Un'analisi comparata della nuova normativa italiana sulla prova processuale del D.N.A a raffronto con il sistema tedesco
Investigation of RELAP Capability to Simulate the LBE Cooling System Thermal-Hydraulic
2004
The paper subject regards the validation of the RELAP5/Mod3.2.2B, the best estimate code modified to deal with fluids of interest for the XADS (eXperimental Accelerator Driven System), a Lead Bismuth Eutettic alloy (LBE) cooled ADS design set up at Ansaldo Industry. The validation will be made exploiting the experimental program carried out on support of XADS design and MEGAPIE experiment, at the ENEA Research Centre of Brasimone (Italy), making use of CHEOPE and CIRCE facilities. The comparison between experimental results and post test calculations allows the check ofthe code capability in simulating the 1Dym fluid-dynamic of heavy metals. In particular, CHEOPE tests have provided data fa…
Generalized power-angle control for grid-forming converters: A structural analysis
2022
Several control schemes have been recently proposed and studied as grid-forming controls for power converters. In all these schemes, the power-angle control loop is the part which defines the fundamental capabilities of the grid-forming control: that control loop governs in fact the inherent synchronization mechanism of the power converter, the power sharing with the other generation sources in the system and the oscillatory characteristics of the converter-based resource. This article introduces a general formulation for the power-angle control characterizing the grid-forming concept for power converters. The generalized power-angle control is based on a polynomial fraction formulation, an…
Annealing of radiation induced oxygen deficient point defects in amorphous silicon dioxide: evidence for a distribution of the reaction activation en…
2011
The selective annealing of point defects with different activation energies is studied, by performing sequences of thermal treatments on gamma irradiated silica samples in the temperature range 300-450 °C. Our experiments show that the dependence on time of the concentration of two irradiation induced point defects in silica, named ODC(II) (standing for oxygen deficient centre II) and the E(γ)(') centre, at a given temperature depends on the thermal history of the sample for both of the centres studied; moreover in the long time limit this concentration reaches an asymptotic value that depends on the treatment temperature alone. These results suggest the existence of a distribution of the a…
Hop: Histogram of patterns for human action representation
2017
This paper presents a novel method for representing actions in terms of multinomial distributions of frequent sequential patterns of different length. Frequent sequential patterns are series of data descriptors that occur many times in the data. This paper proposes to learn a codebook of frequent sequential patterns by means of an apriori-like algorithm, and to represent an action with a Bag-of-Frequent-Sequential-Patterns approach. Preliminary experiments of the proposed method have been conducted for action classification on skeletal data. The method achieves state-of-the-art accuracy value in cross-subject validation.
Energy management of multi-carrier smart buildings for integrating local renewable energy systems
2016
The proposed paper aims at defining a Building Management System (BMS) able to control energy flows inside a smart building integrated with various energy networks and Renewable Energy Resources (RES). The smart building envisaged in this work interacts with different energy carriers and is equipped with cogeneration and RES systems, as well as storage devices, which enable a certain degree of flexibility in the energy usage. The smart building is modelled as a multi-carrier hub, by defining the graphical and mathematical model of the building system. Moreover, the control criteria of the BMS are explained and the implementation of the BMS itself is depicted, along with some early results. …