Ricerc@Sapienza

Conditional efficiency measures are needed when the production process does not depend only on the inputs and outputs, but may be influenced by external factors and/or environmental variables (Z). They are estimated by means of a nonparametric estimator of the conditional distribution function of the inputs and outputs, conditionally on values of Z. For doing this, smoothing procedures and smoothing parameters, the bandwidths, are involved.

The lightning performance evaluation of overhead lines (OHLs) is a very important task, since the vast majority of line outages are due to backflashover caused by a direct lightning stroke. The paper presents results concerning the lightning performance evaluation of existing Italian 150 kV OHLs. An ATP-EMTP Monte Carlo procedure is used to assess the OHL backflashover rate (BFOR): main feature of the procedure is a simplified pi-circuit model able to simulate the transient grounding system behavior with high accuracy and very low computational effort.

A significant majority of overhead transmission lines' (OHLs) outages is due to backflashovers caused by direct lightning strikes: the realistic assessment of the lightning performance is thus an important task. The paper presents the analysis of the lightning performance of an existing 150kVItalian OHL, namely, its backflashover rate (BFOR), carried out by means of anATP-EMTP-based Monte Carlo procedure.

We present detailed Monte Carlo simulations of a simple model of a nematic liquid crystal slot waveguide shifter, investigating the effect of an applied electric external field. The simulations are based on the Lebwohl-Lasher lattice spin model with boundary conditions chosen to mimic the planar alignment as in Silicon Organic Hybrid waveguides and the homeotropic anchoring appropriate for Polydimethylsiloxane polymer walls. The external field is modeled by adding a term to the Hamiltonian which describes its coupling to the mesogenic molecules.

We have performed a detailed Monte Carlo study of photonic devices based on nematic liquid crystal infiltrated in polydimethylsiloxane (PDMS) and in Silicon-Organic Hybrid (SOH) channels, to be used as waveguides. The simulations of a simple model of these slot waveguide shifters have shown the effect of an applied electric external field in two cases with different surface alignments, i.e. planar SOH and homeotropic PDMS. We have investigated the effect of the external field on the optical transmission and the ordering across the cell.

We investigate numerically the homogenization process of a diffusive species in a mixing channel of arbitrary length downstream a microfluidic cross-junction. The channel length, λα, necessary to achieve a prescribed level of mixedness, α, is targeted as primary quantity of interest, and its dependence on the Reynolds number, Re, on the flow ratio between the impinging currents, R, and on the Schmidt number of the solute, Sc, is analyzed.