Abstract: There is described a method of operating a multi-engine system of an helicopter. The multi-engine system has a first turboshaft engine having a first shaft, a second turboshaft engine having a second shaft, a gearbox having a clutch system, and a range of rotation speeds defined as a placarded zone. The method generally has rotating the first shaft at a flight rotation speed when clutched and rotating the second shaft at a first idle rotation speed when unclutched, the first idle rotation speed above the placarded zone; decreasing a rotation speed of the first shaft from the flight rotation speed to a given rotation speed within the placarded zone; decreasing a rotation speed of the second shaft to the given rotation speed; clutching the second shaft; and decreasing the rotation speeds of the first and second shafts to a second idle rotation speed below the placarded zone.

Abstract: A LIDAR-type device for a remote spectroscopy of a matter includes an optical emission channel that includes a laser source and an optical waves frequency generator to generate a first comb, a second comb, and a local comb. Each comb includes at least one stripe. A transmit telescope emits an emission signal. A reception channel includes a receive telescope that receives a signal reflected by the matter traversed by the emission signal and a detection system that detects a first beat signal of the at least one stripe of the local comb with the corresponding first stripe of the first reflected comb, a second beat signal of the at least one stripe of the local comb with the corresponding second stripe of the second reflected comb, and a third beat signal of the at least one first beat signal with the at least one second beat signal.

Abstract: A method of generating frequency combs composed of a predetermined number of rays, wherein the method includes the modulation of a main ray generated by a laser source (20), by a first radiofrequency signal at a first frequency value, by a second radio frequency signal at a second frequency value, and by a third radio frequency signal at a third frequency value. The second frequency value is equal to twice the first frequency value. The third frequency value is equal to three times the first frequency value.

Abstract: A LIDAR-type device for a remote spectroscopy of a matter includes an optical emission channel that includes a laser source and an optical waves frequency generator to generate a first comb, a second comb, and a local comb. Each comb includes at least one stripe. A transmit telescope emits an emission signal. A reception channel includes a receive telescope that receives a signal reflected by the matter traversed by the emission signal and a detection system that detects a first beat signal of the at least one stripe of the local comb with the corresponding first stripe of the first reflected comb, a second beat signal of the at least one stripe of the local comb with the corresponding second stripe of the second reflected comb, and a third beat signal of the at least one first beat signal with the at least one second beat signal.

Abstract: Disclosed is a remote spectroscopy device of the LIDAR type including a module for generating an emission signal, an emission module for sending the emission signal toward a targeted material, a receiving module for receiving a response signal and a module for postprocessing of the response signal to determine a composition of the targeted material. The generating module includes at least two laser sources, each laser source being able to generate a laser signal at a predetermined wavelength, an upstream mixer able to mix the laser signals generated by the different laser sources, and a first modulator able to modulate the composite signal at a first modulation frequency to form the emission signal.

Abstract: A method of generating frequency combs composed of a predetermined number of rays, wherein the method includes the modulation of a main ray generated by a laser source (20), by a first radiofrequency signal at a first frequency value, by a second radio frequency signal at a second frequency value, and by a third radio frequency signal at a third frequency value. The second frequency value is equal to twice the first frequency value. The third frequency value is equal to three times the first frequency value.

Abstract: Disclosed is a remote spectroscopy device of the LIDAR type including a module for generating an emission signal, an emission module for sending the emission signal toward a targeted material, a receiving module for receiving a response signal and a module for postprocessing of the response signal to determine a composition of the targeted material. The generating module includes at least two laser sources, each laser source being able to generate a laser signal at a predetermined wavelength, an upstream mixer able to mix the laser signals generated by the different laser sources, and a first modulator able to modulate the composite signal at a first modulation frequency to form the emission signal.

Abstract: A process and apparatus cools a heat exchange type reaction zone by passing the incoming reactants through heat exchange channels in heat exchange relationship with the reaction zone. The invention simplifies the operation and construction of the heat exchanging type reaction zone by directly communicating reaction channels that contain the reaction with the heating channels that heat reactant across an open manifold located at the end of the channels. Additional reactants, cooling fluids, or other diluents may enter the process directly through the manifold space to permit further temperature control of the reaction zone. The invention promotes better heat transfer efficiency than tube and shell heat transfer arrangements that have been used for similar purposes. The narrow channels are preferably defined by corrugated plates. The reaction channels will contain a catalyst for the promotion of the primary reaction.

Abstract: A process and apparatus cools a heat exchange type reaction zone by passing the incoming reactants through heat exchange channels in heat exchange relationship with the reaction zone. The invention simplifies the operation and construction of the heat exchanging type reaction zone by directly communicating reaction channels that contain the reaction with the heating channels that heat reactant across an open manifold located at the end of the channels. Additional reactants, cooling fluids, or other diluents may enter the process directly through the manifold space to permit further temperature control of the reaction zone. The invention promotes better heat transfer efficiency than tube and shell heat transfer arrangements that have been used for similar purposes. The narrow channels are preferably defined by corrugated plates. The reaction channels will contain a catalyst for the promotion of the primary reaction.