INTRODUCTION The strength of neutron imaging techniques is related to the unique properties of the neutron-matter interaction, such as large penetration depth into bulk materials, sensitivity to light atoms, and high contrast between adjacent elements in the periodic table . The advent of advanced pulsed neutron sources has made available intense fluxes of epithermal neutrons, with energies from above 0.5 eV to the ∼ keV range . These sources offer the additional advantage to use the neutron energy dependence of the neutron cross sections, which allow to enhance the sensitivity to specific elements and isotopes as a function of the neutron energy. State of the art technologies available for neutron-based methods, using cold, thermal and epithermal/fast neutron beams, are currently being applied to study Cultural Heritage artifacts at numerous neutron beam facilities throughout the world . FRASE PIU’ GENERALE PGAA E DETTAGLI SULLA TECNICA (COSA SI FA GIà) STESSA COSA PER NRCA The gamma ray energy spectrum, following radiative absorption, also contains a wealth of information, being element/isotope specific, and shows photo n energy-dependent attenuation due to the spatial location of the emitting nucleus inside the sample [9, 10]. At reactor sources, these properties are at the basis of the Prompt Gamma Activation Analysis (PGAA) technique with thermal and cold neutrons, where high resolution gamma ray energy spectra are recorded [9, 11, 12] without any TOF information. Some of these techniques use neutron resonances for element and isotope identification such as Neutron Resonance Capture Analysis (NRCA) [ref]. This technique use gamma-ray detector to measure the gamma ray emission that follows a resonant neutron capture event in the sample: (n, gamma). The Time Of Flight (TOF) of the recorded event provides information on the specific element in which the resonant radiative absorption takes place. Different elements, and their relative abundances, are therefore distinguished according to element-specific characteristic TOF patterns. COSA FACCIAMO NOI IN PIù E DI DIVERSO A dual TOF-photon energy resolved analysis will go beyond the current state of the art of both PGAA and NRCA, with the potential to enhance the capabilities of both techniques, providing a simultaneous element/spatial sensitivity not currently available. Gamma energy emission spectra for bi-parametric measurements can be recorded by a gamma detector (as germanium detector) equipped with a fast electronics. The bi-parametric acquisition procedure aims to the elemental identification and localization inside extended samples, without recurring to multiple rotations/exposures.

PV power forecast could mitigate the effects of high solar power injection into the Electricity Grid. Two main methods are currently used for PV power generation forecast. A deterministic approach that uses physical based models requiring detailed PV plant information. A data-driven approach based on statistical or stochastic machine learning techniques needing historical power measurements. The main goal of this work is to analyze the accuracy of these different approaches. Two original deterministic and a stochastic model for day ahead PV generation forecast were developed and a detailed error analysis was performed. Four years of site measurements were used to train and test the models. NWP data generated by the WRF models were used as input . Additionally a new parameter, called Clear Sky Performance index, is defined. It is the equivalent of the Clear Sky index for PV power generation forecast and it is here used to develop the stochastic model and an outperforming persistence model. The stochastic model not only was able to correct NWP bias errors, but also provides a better transposition. The deterministic approach leads to a skill score of 35% with respect to the persistence model, while the stochastic approach provides a skill score of 39%.