Search results for "SISTEMI"
showing 10 items of 2026 documents
Analysis and simulations of the primary frequency control during a system split in continental europe power system
2021
The occurrence of system separations in the power system of Continental Europe has been observed in recent decades as a critical event which might cause power imbalances higher than the reference incident specified per system design, representing an actual challenge for the stability and safe operation of the system. This work presents an analysis and simulations of the primary frequency control in the Continental Europe synchronous area in conditions of system separation. The adopted approach is based on fundamental aspects of the frequency-containment reserve process. The analysis takes an actual event into consideration, which determined the separation of the system in January 2021. The …
A new control parameter to predict micro-warping-induced job failure in LPBF of TI6AL4V titanium alloy
2023
Abstract Laser powder bed fusion (LPBF) includes a few printing techniques widely used, in recent years, concerning the additive manufacturing of Ti6Al4V alloys. These produced parts, typically utilized in sectors such as aerospace and biomedical, are characterized by very high added value. It is therefore fundamental to identify the influence of process parameters typical of LPBF technology on the occurrence of warping leading to process failure. This study deals with the characterization of single-track and “micro-scale” level warping phenomena which may lead to protrusion of material over the powder bed and process failure before normal termination. This phenomenon was investigated as a …
Energy Management of a Hybrid Photovoltaic-Wind System with Battery Storage: A Case Report
2019
This work presents a case report related to the management and the monitoring of a hybrid photovoltaic-wind system with battery energy storage, installed at the administrative offices building of the municipality of Valderice (Italy) within the framework of the Italy-Tunisia ENPI cooperation project Le Développement Durable Dans la Production Energétique Dans le Territoire (DE.DU.ENER.T.). The paper describes the hybrid system and briefly reports the monitoring data for a whole year, comparing the real production with the expected one and evaluating some performance indexes of the system. The performance indexes are very simple and have been defined only with the purpose of sh…
An efficient proposal for the application of simulated annealing algorithms
2014
Complex nonlinear optimization problems require specific resolution techniques. These problems are often characterized by a solution space that presents many local optima. In these cases, local search algorithms, as the classical descent neighborhood search method, have a heavy drawback: the optimization algorithm generally converges towards a local minimum. To avoid getting trapped in a local minimum, the optimization algorithm must allow to accept worse solutions than the current one. Several kinds of algorithms have been ideated for this purpose and they differ for the acceptance criteria of a pejorative solution. Among such algorithms it is possible to remember the Taboo Search (TS) and…
Blogging as a research and educational tool: a three years experience
2008
Abstract Blogging can be also used to share knowledge in research and education. We have been using many blogs with the following purposes. One goal has been to raise awareness about research methods in the information technology field by supporting information exchange, collaboration, and cooperation between researchers. We have been using a common blog for 3 years to share inter- and intra disciplinary knowledge among us. We have also collected stories and interviewed colleagues and friends. An other goal is the use of blogs during our teaching experience as an instrument to support the exchange of knowledge with students. A comparison of the use of blogging is presented with positive and…
A constrained genetic algorithm to optimize a maintenance global service
2014
It is herein developed an approach to optimize the maintenance services policy related to a Global Service Contract. In particular, the latter requires the performing of corrective maintenance and replacements of the failed components on a set of equal vehicles of a logistic Company. The tackled problem concerns the determination of an effective opportunistic maintenance policyon the basis of which when a fault occurs, it is replaced the failed component and, depending on the age of the others components, also replacements of others suitable components are performed, even if they are not yet broken, thus saving a substantial amount of system downtime. The problem is mathematically formulate…
Il paradigma mafioso dentro il modello della criminalità organizzata
2021
Interrogarsi sul metodo mafioso significa fare i conti con le differenti definizioni che della mafia sono state fornite, in un’ottica che non può che essere comparativa e diacronica. Non si possono, infatti, ignorare né le differenti declinazioni del modello organizzativo criminale nei diversi contesti territoriali, né la sua evoluzione nel tempo, né le modifiche intervenute con l’ampliarsi dello scenario internazionale e con la nascita delle cosiddette “nuove mafie”. Occorre, quindi, verificare gli elementi di mutazione riscontrati nelle maggiori organizzazioni criminali mafiose che operano in Italia; da una parte, spingendo l’attenzione verso gli scenari internazionali e, dall’altra, rile…
Waiting for a new leader: Eras and transitions in Cosa Nostra
2019
Partendo dal controverso dibattito che negli ultimi anni ha visto in Italia – soprattutto i mezzi di comunicazione di massa e le agenzie investigative – disputare sullo “stato di salute” delle organizzazioni criminali mafiose, quasi a volerne stilare una discutibile classifica di offensività e di pericolosità, il capitolo si interroga sull’attuale e delicata fase attraversata da Cosa Nostra, facendo ricorso a una prospettiva analitica multiproblematica e multidisciplinare (rielaborando il cosiddetto paradigma della complessità proposto da Umberto Santino alla luce dei più recenti studi e delle nuove prospettive analitiche emerse) e dando conto delle numerose ricerche (oggi spesso orientate …
Blockchain for power systems:Current trends and future applications
2020
Abstract Today, the blockchain is synonymous of technological innovation, being recognized among the 10 top strategy technologies in 2018 by the consulting company Gartner, it is more and more adopted in different sectors. However, the initial enthusiasm around this technology is going beyond the peak of inflated expectations, towards more stable applications in money transactions, cryptocurrencies and Digital Commodity Exchanges. Essentially, misguided efforts, the overuse of blockchain, and the Bitcoin's price drop have been the main reasons for this decay in expectations. Nevertheless, the exploitation of the blockchain technology in the power systems area appears largely underexplored, …
Room Temperature Instability of E′γ Centers Induced by γ Irradiation in Amorphous SiO2
2008
We study by optical absorption measurements the stability of E'(gamma) centers induced in amorphous silica at room temperature by gamma irradiation up to 79 kGy. A significant portion of the defects spontaneously decay after the end of irradiation, thus allowing the partial recovery of the transparency loss initially induced by irradiation. The decay kinetics observed after gamma irradiation with a 0.6 kGy dose closely resembles that measured after exposure to 2000 pulses of pulsed ultraviolet (4.7 eV) laser light of 40 mJ/cm(2) energy density per pulse. In this regime, annealing is ascribed to the reaction of the induced E'(gamma) centers with diffusing H(2) of radiolytic origin. At higher…