Abstract: Method for tracking and exploiting at least one environmental parameter such as cleanness in an urban setting; method comprising the following successive steps: —Planning measurements of at least one environmental parameter; —Tracking in real-time said parameter by means of a camera located on-board a vehicle or fastened to a static holder; —Geo-positioning the parameter; —Classifying the parameter depending on the characteristics thereof, such as category, danger or typology; —Improving the environmental parameter based on the data obtained in the 2 preceding steps. The invention also relates to a device using said method.

Abstract: Method for tracking and exploiting at least one environmental parameter such as cleanness in an urban setting; method comprising the following successive steps: —Planning measurements of at least one environmental parameter; —Tracking in real-time said parameter by means of a camera located on-board a vehicle or fastened to a static holder; —Geo-positioning the parameter; —Classifying the parameter depending on the characteristics thereof, such as category, danger or typology; —Improving the environmental parameter based on the data obtained in the 2 preceding steps. The invention also relates to a device using said method.

Abstract: The invention relates to a hollow-stem valve for an internal combustion engine. The valve has a ratio of wall thickness to stem diameter of less than 1:3. The aim of the invention is to minimize the deformation of the valve head. To this end, the valve disk rests directly against the stem.

Abstract: The supersonic distributor for the inlet stage of a turbomachine comprises an outer case, a hub, and a set of peripheral blades disposed in a ring and attached to the hub to provide supersonic speed fluid passages between the blades to transform a flow at high pressure and low speed into a supersonic flow at low pressure. The blades are disposed radially in regular manner within a fluid feed torus. In a section developed on a line corresponding to a given radius, i.e. in a blade-to-blade plane, the blades define a profile in the form of a two-dimensional half-nozzle. This profile has a rectilinear upstream portion, a bulge defining a throat for accelerating the flow to a Mach number equal to 1, the throat being of section that varies with radius, and a downstream portion which terminates in a region of uniform flow at a trailing edge which may be truncated perpendicularly to the axis of rotation.