Abstract: A method is described for the characterization of atmospheric particles by means of a lidar device. The method provides to send a laser pulse in the atmosphere, a part of which is directly backscattered by the particles in the atmosphere. A reflecting optical device is provided, that is positioned at a predetermined distance d from the lidar device, whereby a part of the laser pulse that directly reaches the reflecting device is backreflected and is later backscattered by the particles in the atmosphere thus generating a counterpropagating backscattering signal directed towards the reflecting device, which signal reaches the reflecting device and is backreflected towards the lidar device. The lidar device detects the direct backscattering and counterpropagating signals. The optical characteristics of the particles are determined on the basis of the direct backscattering signal and the counterpropagating backscattering signal.

Abstract: A photovoltaic device optical system for enhanced light harvesting with a transparent layer of dielectric material having on one side an array of micro-lenses and on the opposite side a metal reflective film with an array of openings. The micro-lenses focus direct sunlight impinging thereon through the openings, to separate direct sunlight and diffuse sunlight. The photovoltaic device has a first photovoltaic cell system for the exploitation of the direct sunlight located in the opposite hemi-space of the micro-lenses array with respect to the plane of the openings array and a second photovoltaic cell system for the exploitation of diffuse sunlight, located in the same hemi-space containing the micro-lenses array with respect to the plane of the openings array.

Abstract: A method is described for the characterization of atmospheric particles by means of a lidar device. The method provides to send a laser pulse in the atmosphere, a part of which is directly backscattered by the particles in the atmosphere. A reflecting optical device is provided, that is positioned at a predetermined distance d from the lidar device, whereby a part of the laser pulse that directly reaches the reflecting device is backreflected and is later backscattered by the particles in the atmosphere thus generating a counterpropagating backscattering signal directed towards the reflecting device, which signal reaches the reflecting device and is backreflected towards the lidar device. The lidar device detects the direct backscattering and counterpropagating signals. The optical characteristics of the particles are determined on the basis of the direct backscattering signal and the counterpropagating backscattering signal.

Abstract: A radiometer for measuring the total effective UV radiance of the type comprising, in an optical pathway sequence, a diffuser, an interference filter and a detector. Said interference filter comprises a plurality of alternating layers of magnesium fluoride and zirconium oxide, where the diffuser/interference filter/detector system has a spectral response equivalent to the erythema action curve CIE.

Abstract: A method is for forming three-dimensional micro- and nanostructures, based on the structuring of a body of material by a mould having an impression area which reproduces the three-dimensional structure in negative form. This method includes providing a mould having a substrate of a material which can undergo isotropic chemical etching, in which the impression area is to be formed. An etching pattern is defined on (in) the substrate, having etching areas having zero-, uni- or bidimensional extension, which can be reached by an etching agent. A process of isotropic chemical etching of the substrate from the etching areas is carried out for a corresponding predetermined time, so as to produce cavities which in combination make up the impression area. The method is advantageously used in the fabrication of sets of microlenses with a convex three-dimensional structure, of the refractive or hybrid refractive/diffractive type, for forming images on different focal planes.

Abstract: Optical system for detecting the concentration of combustion products operating in situ and at high temperature based on measurement of the optical absorption of a gaseous mixture of combustion products through a photodetecting sensor based on gallium nitride (GaN), aluminium nitride (AlN), indium nitride (InN) and corresponding alloys. The operating temperature of the sensor preferably lies between 500° C. and 700° C., but the resistance of the active material permits use at even higher temperatures. This system can be used to measure the concentration of chemical species present in combustion products directly at their outlet, where the high operating temperature makes it possible to avoid fouling of the sensor caused by carbonaceous and non-carbonaceous deposits. The rate of response of the system is less than or equal to 1 millisecond and makes it possible to adjust the parameters of an associated combustion process control system in real time.

Abstract: A method is described for the identification of a party authorised to have the benefit of a service delivered by a provider party via a telematics network, in which the provider party and each user party are connected to the network by means of a respective electronic communications and processing system (S, C), and the provider party requests a temporary password (PWD) identifying the user party to allow access to the services delivered.