Abstract: An aircraft engine, has: an upstream stator having upstream stator vanes distributed about a central axis; and a downstream stator having downstream stator vanes distributed about the central axis, the downstream stator located downstream of the upstream stator, a number of the upstream stator vanes different than a number of the downstream stator vanes, the downstream stator vanes including: a first vane, a major portion of a leading edge of the first vane circumferentially overlapped by one of the upstream stator vanes; and a second vane differing from the first vane by a geometric parameter, the geometric parameter causing the second vane to have one or more of: a stiffness greater than that of the first vane, and a major portion of a leading edge of the second vane circumferentially overlapped by another one of the upstream stator vanes.

Abstract: An aircraft engine, has: an upstream stator having upstream stator vanes circumferentially distributed about a central axis; and a downstream stator having downstream stator vanes circumferentially distributed about the central axis, the downstream stator located downstream of the upstream stator relative to an airflow flowing within a core gaspath of the aircraft engine, a number of the upstream stator vanes being different than a number of the downstream stator vanes, the downstream stator vanes including: a first vane made of a first material, a major portion of a leading edge of the first vane circumferentially overlapped by one of the upstream stator vanes, and a second vane made of a second material having a greater stiffness, strength, and/or ductility than that of the first material, a major portion of a leading edge of the second vane exposed via a spacing defined between two of the upstream stator vanes.

Abstract: An aircraft engine, has: an upstream stator having upstream stator vanes circumferentially distributed about a central axis; and a downstream stator having downstream stator vanes circumferentially distributed about the central axis, the downstream stator located downstream of the upstream stator relative to an airflow flowing within a core gaspath of the aircraft engine, a number of the upstream stator vanes being different than a number of the downstream stator vanes, the downstream stator vanes including: a first vane made of a first material, a major portion of a leading edge of the first vane circumferentially overlapped by one of the upstream stator vanes, and a second vane made of a second material having a greater stiffness, strength, and/or ductility than that of the first material, a major portion of a leading edge of the second vane exposed via a spacing defined between two of the upstream stator vanes.

Abstract: The present invention relates to a method for preparing carboxylic acids, in particular mono- and dicarboxylic acids, by oxidative cleavage of a vicinal diol. According to the invention, said method consists of reacting a vicinal diol of formula I: where: p is an integer comprised between 1 and 6; R1 and R2 are, separately: an alkyl or hydroxyl group having 1 to 12 carbon atoms; a —(CH2)n—C02M group where n, which can be identical or different in R1 and R2, is an integer comprised between 1 and 11 and M is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or an alkaline cation; or R1 and R2 jointly form an alkylene —(CH2)m- group where m is an integer comprised between 2 and 10, preferably between 2 and 6; with industrial-grade sodium hypochlorite (or bleach), in the absence of an organic solvent and without adding a catalyst, preferably at room temperature. The invention can be used for recycling natural vegetable oils.

Abstract: The invention concerns a method for preparing glycerol carbonate. This method consists of making urea and glycerol react at a temperature substantially between 90.degree. C. and 220.degree. C. in the presence of a catalyst bearing Lewis acid sites, in particular metallic or organometallic salts or supported metallic compounds. The invention enables glycerol carbonate to be obtained, by a catalytic carbamoylation/carbonation reaction, in a highly pure state under economic conditions.