Abstract: A process for olefin polymerization in a reaction vessel, said process comprising polymerizing at least one &agr;-olefin in a polymerization stage employing a catalyst feed comprising 1) a first catalyst composition having at least two active catalytic sites capable of producing a first set of polymer components; 2) a second catalyst composition having at least two active catalytic sites capable of giving essentially the same set of polymer components as produced by the catalyst in feed (1) under the same polymerization conditions but these components in a different ratio to those produced by the catalyst composition of feed (1); wherein the amounts of catalyst compositions (1 and 2) fed into the reaction vessel are independently controlled.

Abstract: An actuating device for a multi-nozzle ink jet printhead, which includes a linear array of electromechanical transducers some of which are configured as actuator fingers associated with the nozzles of the printhead while others are configured as support fingers disposed between the actuator fingers, wherein each transducer has a first and a second electrode and is adapted to expand and contract in accordance with a voltage applied between the first and second electrodes, wherein the totality of the transducers consists of at least one group which includes a plurality of actuator fingers and a plurality of support fingers, and control means are associated with each group for applying a voltage that depends on the number of active actuator fingers in this group, to the first electrodes of all support fingers of the group.

Abstract: A piezoelectric actuator having a body with a front face, a rear face opposite to the front face, and second side faces opposite to one another, the body being formed by several active layers of piezoelectric material with internal electrodes intervening therebetween, wherein the internal electrodes include a first group of electrodes extending to the rear face of the body and connected to a first external electrode, and a second group of electrodes extending to the front face of the body and connected to a second external electrode, wherein the electrodes of the first group extend to the first side face of the block and are buried in the block near the second side face thereof, and the electrodes of the second group extend to the second side face of the block and are buried in the block near the first side face.

Abstract: A piezoelectric actuator for an ink jet printhead, including:

Abstract: A process for the polymerization of ethylene and optionally &agr;-olefins to form ethylene homopolymer or copolymers having a broad molecular weight distribution, comprising polymerization of 100-80 wt. % of ethylene and 0-20 wt. % of comonomer in the presence of two independent, simultaneously present catalysts A and B, wherein catalyst A, deposited on an inorganic support, comprises chromium in a predominantly oxidant state of 2 and catalyst B comprises a bis-cyclopentadienyl chromium compound reacted with an inorganic support.