Abstract: The invention relates to a method and device for diagnosing the operation of a photovoltaic module string. The method involves acquiring a series of current and voltage measurements forming a current versus voltage curve, known as the I(V) curve, and the steps of: transforming (46) into polar coordinates, each pair of current and voltage values of the I(V) curve, calculating (48-54) parameters of a first electrical model and second electrical model each approximating said I(V) curve, as well as a first cost representative of a deviation between said first model and said I(V) curve, and a second cost representative of a deviation between said second model and said I(V) curve, using a distance metric in the polar coordinate space, selecting (56) an electrical estimation model for estimating the I(V) curve and diagnosing (58) operation based on this selected electrical estimation model.

Abstract: The invention concerns a catalyst comprising palladium on an oxide of aluminium support. In the calcined state, the oxide of aluminium support has a diffractogram obtained by X ray diffraction comprising peaks which correspond to the following interplanar spacings and relative intensities: Interplanar spacings d (10?10 m) Relative intensities ±5 × 10?3 d I/I0 (%) 4.54? ?3-10 2.70-2.75 ?5-25 2.41? 35-45 2.28? 15-30 2.10? ?0-10 1.987 30-50 1.958 30-50 1.642 0-5 1.519 10-20 1.