SURFACE ROUGHNESS PREDICTION OF ELECTRO-DISCHARGE MACHINED COMPONENTS USING ARTIFICIAL NEURAL NETWORKS

Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism, which involves the formation of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena negatively affecting the surface integrity of EDMed workpieces need to be taken into account and studied in order to achieve the optimization of the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling tec…

Prevalenza dei polimorfismi FV Leiden, FII G20210A e iperomocisteinemia in pazienti con stroke ischemico

Effetti della temperatura dell'acqua sull'idratazione di nuotatori di fondo

Modelling steel jacketed RC columns: Remarks by experimental-numerical comparisons

The recent large use of nonlinear seismic assessment techniques requires the definition of highly reliable computational models. The retrofitting or strengthening of RC columns by steel angles and battens is a commonly adopted technique, used to improve strength and deformation capacity of existing RC buildings. In the case of steel angles not directly loaded, the numerical definition of the cross-section model has to be handled carefully since it is affected by more uncertainties. The vertical load carried by the angles is a function of the lateral confinement pressure, the cohesion and the friction coefficient between the materials, parameters which are not always easy to predict. The pap…

Studio preliminare sulla diversità della megafauna dei barren mediterranei

Relazioni tra parametri biometrici in Marthasterias glacialis (L.) (Asteroidea)

Biometric parameters of the Asteroid echinoderm Marthasterias glacialis (L.) were measured at Ustica Island MPA (SW Tyrrhenian Sea). Wet weight was correlated with tip-to-tip (arm-span) diameter, central disk, arm length, arm width and arm height. Results show high positive correlation between weight and arm height, suggesting a new useful method to estimate starfish size also for in situ measurements.

Definizione di Mappe di Vulnerabilità Sismica per le Aree Mediterranee Transfrontaliere: Il caso di Lampedusa

La possibilità di individuare e quantificare le principali criticità legate ad eventi catastrofici naturali su un territorio, consente di pianificare strategie e interventi adeguati da parte degli organismi di Protezione Civile coinvolti in emergenze locali e internazionali. Il rischio sismico dipende soprattutto dalla vulnerabilità degli edifici appartenenti alle aree urbane. La conoscenza degli scenari di rischio è dunque fondamentale per pianificare e gestire azioni di assistenza in caso di emergenza e non può prescindere dalla quantificazione e localizzazione della vulnerabilità sismica. Il presente studio propone una procedura per la definizione di mappe di vulnerabilità sismica in ter…

Integrity of predator assemblages controls the abundanceof the alien crab Percnon gibbesi

Ecosystem resistance to species invasion is considered to be related to the abundance and diversity of native species (i.e. diversity-resistance hypothesis). In particular, the integrity of predator assemblages may enhance the control of prey populations through direct and indirect interactions (e.g.: different predation strategies by different predators, facilitative interactions among predators). Depletion of predators due to overfishing is therefore expected to enhance the abundance and ultimately the spread of alien prey species. Manipulative field experiments were performed to evaluate the effects of different abundance and diversity of predator assemblages on the invasion success of t…

Predation on sea urchin by Marthasterias glacialis (L.).