Ottimizzazione pratiche operative in un forno elettrico ad arco (iCSMelt®)

Il tool “iCSMelt® - intelligent Care Steel Melting”, è stato sviluppato dal Centro Sviluppo Materiali (CSM)con lo scopo di ottenere pratiche operative ottimizzate (OOP – Optimized Operating Practices) per la gestionedel processo di fusione nel Forno Elettrico ad Arco (FEA) una volta definita la funzioni obiettivo di interesse(OF - Objective Functions), come ad esempio Power on, costo della colata, consumo di energia.L’articolo presenta i risultati dell’applicazione di iCSMelt® presso l’impianto FEA DC di Duferco La Louviere(DLL) nel progetto “Control and optimisation of scrap charging strategies and melting operations to increasesteel recycling ratio - CONOPT-SCRAP” condotto con il contributo finanziario del fondo di ricerca per il carbonee l’acciaio della Comunità Europea (Research Fund for Coal and Steel)

Fixed-point elimination in the intuitionistic propositional calculus

It is a consequence of existing literature that least and greatest fixed-points of monotone polynomials on Heyting algebras-that is, the algebraic models of the Intuitionistic Propositional Calculus-always exist, even when these algebras are not complete as lattices. The reason is that these extremal fixed-points are definable by formulas of the IPC. Consequently, the $\mu$-calculus based on intuitionistic logic is trivial, every $\mu$-formula being equivalent to a fixed-point free formula. We give in this paper an axiomatization of least and greatest fixed-points of formulas, and an algorithm to compute a fixed-point free formula equivalent to a given $\mu$-formula. The axiomatization of the greatest fixed-point is simple. The axiomatization of the least fixed-point is more complex, in particular every monotone formula converges to its least fixed-point by Kleene's iteration in a finite number of steps, but there is no uniform upper bound on the number of iterations. We extract, out of the algorithm, upper bounds for such n, depending on the size of the formula. For some formulas, we show that these upper bounds are polynomial and optimal

A Non-wellfounded, Labelled Proof System for Propositional Dynamic Logic

We define a infinitary labelled sequent calculus for PDL, G3PDL^{\infty}. A finitarily representable cyclic system, G3PDL^{\omega}, is then given. We show that both are sound and complete with respect to standard models of PDL and, further, that G3PDL^{\infty} is cut-free complete. We additionally investigate proof-search strategies in the cyclic system for the fragment of PDL without tests

Software Tool Support for Modular Reasoning in Modal Logics of Actions

International audienc

Dietary and lifestyle habits of drinkers with preference for alcoholic beverage: Does it really matter for public health? a review of the evidence

Although the detrimental effects of heavy drinking in terms of health are well-documented in the literature, there are inconsistent findings regarding the safety of light-to-moderate alcohol consumption. In particular, little is still known about the consumption of specific alcoholic beverages in combination with dietary habits and lifestyle, which in turn could influence health status. Thus, the aim of this review is to summarise and critically evaluate the evidence of a relationship between preference for alcoholic beverages and consumer dietary and lifestyle habits. A literature search retrieved 3,887 articles. By removing duplicates and articles which were not relevant, the final number of articles was 26. The adherence to a healthier diet and lifestyle was generally observed in light-to-moderate alcohol consumers, especially when wine was the preferred beverage. Considering the potentially strong impact of drinking patterns on health and the risk of developing chronic diseases, the data summarised in this review highlight that alcoholic beverage preferences, drinking patterns, dietary patterns and lifestyle should be studied together. Any future epidemiological studies should analyse the relationship between alcohol consumption and the abovementioned correlations with respect to impact on health. © 2021 International Viticulture and Enology Society-IVES

Study on the Pneumatic Lime Injection in the Electric Arc Furnace Process: An Evaluation on the Performance Benefits

The pneumatic lime injection during the electric arc furnace (EAF) process by insufflation lances mounted on the furnace walls has gained much interest in the latest years. The main advantages, in comparison to the traditional procedure of lime lumps addition within the scrap bucket, can be summarized in raw materials consumption reduction, foaming benefits, operational cost benefits, and improvement in environmental aspects. In the proposed work, the advantages of a new lime injection system developed by Unicalce S.p.A. and installed on a 90 t EAF of Acciaierie di Calvisano are analyzed. Data from more than 1200 heats are acquired and compared with the traditional practice from an energetically and emissions point of view. To evaluate the benefits on the slag foamability, several slag samples, taken at the beginning and at the end of refining stage, are analyzed through isothermal solubility diagrams (ISDs). The ISD analysis results are then compared and validated with the total harmonic distortion (THD) of the arc in the corresponding heat. The upgrade to lime injection drives to considerable savings in electrical consumptions, oxygen, methane, and lime, with an overall save of more than 4,000 t year−1 of equivalent CO2

Evaluation of the effects of lime injection on the Electric Arc Furnace performances

In recent years, the pneumatic injection of lime in Electric Arc Furnaces by the use of insufflation lances has acquired interest in becoming a viable tool for the steelmaking industry, thanks to its surprising results in terms of raw materials consumption reduction, foaming benefits, operational cost benefits and improvement in environmental aspects. Acciaierie di Calvisano steelmaking plant, in collaboration with Unicalce S.p.A., decided to implement a new system of lime injection, in place of the traditional procedure, which is based on lime addition in lumps within the scrap bucket. The benefits of injecting lime in fine particles, compared to the standard technique were evaluated from energy, consumptions and emissions point of view. Data for more than 1200 heats was acquired and several slag samples were analyzed. Results showed considerable savings in electrical consumptions, oxygen, methane and lime, with an overall save of more than 4,500 t/year of equivalent CO2