Ricerc@Sapienza

An improved algorithm to generate skeletal mechanisms from the original detailed chemical kinetic mechanisms is proposed. The new algorithm builds on the computational singular perturbation (CSP) framework, by adding an additional layer of automation based on the tangential stretching rate (TSR) and the species’ participation index to TSR. The main advantage of the new approach is that it does not require the specification of a set of target species.

Turbulent premixed flames at high Karlovitz numbers exhibit highly complex structures in different reactive scalar fields to the extent that the definition of the flame front in an unambiguous manner is not straightforward. This poses a significant challenge in characterizing the observable turbulent flame behaviour such as the flame surface density, turbulent burning velocity, and so on. Turbulent premixed flames are reactive flows involving physical and chemical processes interacting over a wide range of time scales.

In this study Ni-Co-W alloys have been produced by electrodeposition on Al net. Two electrolytic baths, with and without sodium citrate, having the same metal ion content (20 g/l Ni, 8 g/l Co and W in the range 2-8 g/l) and boric acid content 20 g/l, have been used. Temperature and current density operative conditions have been varied in the range 30-60 degrees C and 260-350 A/m(2) respectively.

Energy costs, carbon dioxide emissions, security of supply and system stability are common challenges in small islands. Many European islands have become pilot sites of energy innovation, but this green transition goes slowly in other ones usually not connected to the national grid.

The forecasting of electricity load is considered as an essential instrument, especially in countries with a restructured electricity market. The mid-term prediction is performed for the period within 1 month to 1 or 2 years and it is important for mid-term planning, including planning of repairs and economic exploitation of power systems, which are related to the reliability of the system directly. The forecast horizon in this paper is monthly and on a daily basis (peak load).

The paper proposes a methodological approach to manage the electric vehicles recharging in an isolated power system characterized by low short circuit power. Focusing on harmonic disturbances, current harmonics injected in the network depend on the specific EV power converter. The model carried out allows for the evaluation of harmonic disturbances under variable conditions for non-linear loads and their harmonic spectra. The methodology allows estimating both current and voltage total harmonic distortion (THDV, THDI) at the point of common coupling (PCC).