Abstract: A nebulizer for analytical purposes includes a needle through which flows a liquid to be nebulized. The liquid flows from the needle onto a diaphragm planar surface that is vibrated in successive pulses. A continuous bridge of the liquid subsists between the liquid and the planar surface when the diaphragm is in the non-vibrating state. The liquid is nebulized to an aerosol when the diaphragm is pulsed. The needle and diaphragm are always spaced from each other. A wick on the planar surface in contact with the film removes excess amounts of the liquid not involved in forming the aerosol. The diaphragm vibration is pulsed by a piezoelectric crystal that responds to an FM wave whose frequency is swept over a band spanning the resonant frequency of the crystal. The crystal is configured as a spherical segment to direct a focused pressure wave on the diaphragm via a liquid medium.

Abstract: The contrast ratio of an image intensifier of the photocathode-amplifier-phosphor type is increased by using a fiber optic plate of which the thickness is reduced to such extent that the plate may not be able to function as a vacuum seal or an electrical insulator when a typical voltage for the operation of the intensifier is applied to the phosphor layer. This relatively thin fiber optic plate is placed entirely inside a vacuum, protected from the atmospheric pressure by a thick output window plate which is optically transparent.

Abstract: In an image converter tube, the brightness contrast of the output picture is reduced by light which is internally reflected at the surfaces of the window through which the image is viewed. The contrast can be improved by making the window partially light-absorbing, at the expense of a reduction in the overall optical gain. This gain varies considerably from tube to tube. By adding an external filter on the output window, the transmission of the filter can be chosen for each tube to provide the minimum acceptable gain and thus the maximum obtainable contrast.

Abstract: An electrical-to-acoustic wave transducer contains an array of piezoelectric elements connected to wave-delay circuits to generate a directed acoustic beam and to receive a similarly directed, reflected beam. The distance of a reflecting object is sensed by the time delay of the reflected wave. The apparatus is adapted to sense reflections from both the Fresnel region and the far-field of the array. During the time when reflections from nearby objects in the Fresnel region are received, the effective aperture of the array is reduced by disconnecting elements near its extremities or reducing their gain, producing a narrower beam for improved angular resolution.