Abstract: A method for preparing a perovskite oxide nanopowder by way of applying an ultrasonic nebulizer provides a narrow size distribution of spherical particles with minimum particle aggregation.

Abstract: Air-dielectric sandwich structures for electrically tunable microwave devices provide two types of layered structures; one type comprising a first dielectric material, a second dielectric material, an air gap between the first and second dielectric materials and an electromechanical actuator for adjusting the width of the air gap by moving the first or second dielectric materials, and the other type comprising a dielectric material, a metal wall, an air gap between the dielectric material and the metal wall and an actuator for adjusting the width of the air gap by moving the dielectric material or the metal wall. The tunable microwave devices including the air-dielectric sandwich structure are elaborated such as a tunable dielectric resonator, a band stop and a band pass filter, a phase shifter and a phase array antenna.

Abstract: This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

Abstract: This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.