Abstract: The present invention relates to a method for synthesizing polyesters or copolyesters having a mean molar mass in mass MW, greater than 10000, by means of a direct polyesterification reaction between a diacid, diester, hydroxyacid, or hydroxyester and a diol, or between hydroxyacids or hydroxyesters, said method being characterized in that said polyesterification reaction is carried out at a temperature of 60 to 150° C. at atmospheric pressure in a reaction medium including at least one acidic ionic liquid consisting of an anion and a cation, the electrical charges of which balance each other out, and wherein at least the cation is a strong acid according to the Bronsted definition, or comprises a grouping that is a strong acid according to the Bronsted definition.

Abstract: The present invention consists in an optical device comprising an optical component and an optical medium with different refractive indices, said optical component being at least partly immersed in said optical medium, which device is characterized in that said optical medium contains a salt that is in the liquid state in the range of temperatures at which said optical component is used and stored, i.e. in a range of temperatures generally from ?40° C. to +200° C. The optical component may in particular be a Bragg long-period grating (LPG) or a photonic crystal fiber.

Abstract: The present invention consists in an optical device comprising an optical component and an optical medium with different refractive indices, said optical component being at least partly immersed in said optical medium, which device is characterized in that said optical medium contains a salt that is in the liquid state in the range of temperatures at which said optical component is used and stored, i.e. in a range of temperatures generally from ?40° C. to +200° C. The optical component may in particular be a Bragg long-period grating (LPG) or a photonic crystal fiber.

Abstract: An electromechanical switch of the contactor or circuit-breaker type with adjacent contacts, which are provided on respective mobile and fixed contact parts. This arrangement defines a narrow ionization slot which is maintained at the start of contact opening in order to cause a secondary arc to fire substantially perpendicular to the contact opening direction constituting a shunting arc to eliminate the time duration of the contacts and switch legs.