Abstract: A leading edge structure (1) for a flow control system of an aircraft (101) including a double-walled leading edge panel (3) surrounding a plenum (7). The leading edge panel (3) has a first side portion (11) extending to a first attachment end (17), a second side portion (13) extending to a second attachment end (19), an inner wall element (21) facing the plenum (7), an outer wall element (23) for contact with an ambient flow (25), a core assembly (97). The outer wall element (23) includes micro pores (31) forming a fluid connection between the core assembly (97) and the ambient flow (25). The inner wall element (21) includes openings (33) forming a fluid connection between the core assembly (97) and the plenum (7). The outer wall element (23) extends from the first attachment end (17) to the second attachment end (19).

Abstract: A leading edge structure (1) for a flow control system of an aircraft (101) including a double-walled leading edge panel (3) with a first side portion (11) extending to a first attachment end (17), a second side portion (13) extending to a second attachment end (19), an inner wall element (21) facing a plenum (7), an outer wall element (23) facing ambient flow (25), and a core assembly (97). The outer wall element (23) includes micro pores (31) and the inner wall element (21) includes openings (33) which form a fluid connection from ambient flow, through the core assembly (97) and to the plenum (7). The thickness of the outer wall element is reduced due to the first attachment end (17) and/or at the second attachment end (19) attached to the inner wall element (21) by both bonding and fasteners (85, 87, 89, 91).

Abstract: Method for monitoring the velocity of growing polymer particles flowing in a two-phase stream during a polymerization process, said method comprising measuring the degree of attenuation in the propagation of light in said two-phase stream by means of a photometric instrument, said photometric instrument comprising: one or more transmitting optical waveguides connecting one or more light sources to said two-phase stream, one or more receiving optical waveguides connecting said two-phase stream to a light detector.

Abstract: Process for the gas-phase polymerization of one or more alpha-olefins in the presence of a catalyst system, the process comprising: contacting in a continuous way one or more of said alpha-olefins with said catalyst system in a prepolymerization reactor, wherein the reaction is carried out in a liquid medium at a temperature ranging from 23° to 50° C.; feeding in continuous the prepolymer obtained in step a) into a gas-phase reactor having interconnected polymerization zones, where the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity, leave said downcomer and are reintroduced into said riser; wherein the prepolymer obtained from step a) is continuously fed at a section of said riser characterized by an upwardly gas velocity higher than 3.0 m/s.

Abstract: A process for preparing heterophasic propylene copolymers by polymerizing propylene in the presence of a polymerization catalyst and hydrogen as a molecular weight regulator, the process comprising the following steps: a) polymerizing in gas- or liquid-phase propylene to prepare a crystalline polymer fraction; b) copolymerizing ethylene with propylene and/or 1-butene, and optionally one or more alpha-olefin comonomers C5-C12, in a gas-phase reactor having interconnected polymerization zones, wherein the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity.

Abstract: Process for the gas-phase polymerization of one or more alpha-olefins in the presence of a catalyst system, the process comprising: contacting in a continuous way one or more of said alpha-olefins with said catalyst system in a prepolymerization reactor, wherein the reaction is carried out in a liquid medium at a temperature ranging from 23° to 50° C.; feeding in continuous the prepolymer obtained in step a) into a gas-phase reactor having interconnected polymerization zones, where the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity, leave said downcomer and are reintroduced into said riser; wherein the prepolymer obtained from step a) is continuously fed at a section of said riser characterized by an upwardly gas velocity higher than 3.0 m/s.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: A process for preparing heterophasic propylene copolymers by polymerizing propylene in the presence of a polymerization catalyst and hydrogen as a molecular weight regulator, the process comprising the following steps: a) polymerizing in gas- or liquid-phase propylene to prepare a crystalline polymer fraction; b) copolymerizing ethylene with propylene and/or 1-butene, and optionally one or more alpha-olefin comonomers C5-C12, in a gas-phase reactor having interconnected polymerization zones, wherein the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity.

Abstract: Method for monitoring the velocity of growing polymer particles flowing in a two-phase stream during a polymerization process, said method comprising measuring the degree of attenuation in the propagation of light in said two-phase stream by means of a photometric instrument, said photometric instrument comprising: one or more transmitting optical waveguides connecting one or more light sources to said two-phase stream, one or more receiving optical waveguides connecting said two-phase stream to a light detector.

Abstract: A method of making a multilayer printed circuit upon a single crystal substrate for the mounting thereon of a semiconductor laser and an optical fibre pigtail located in a crystallographically etched groove in the substrate wherein all the photolithographic processing required to create the multilayer printed circuit is performed prior to the etching of the groove.