Abstract: A horn antenna includes smooth-walls with multiple slope discontinuities. The horn antenna may have more than an octave bandwidth with a 2.25:1 bandwidth ratio to cover the frequencies of 20 GHz, 30 GHz, and 45 GHz, or all the desired bands for military or other communications.

Abstract: A scanning wide-field telescope includes a primary reflecting mirror and a corrector assembly. The corrector assembly corrects light beams for spherical aberration imposed on the light beams by the primary reflecting mirror. The corrector assembly is located between the primary reflecting mirror and a viewing end of the telescope, and is configured to move to multiple optical focal points of the primary reflecting mirror.

Abstract: A system and a method to detect biological and chemical agents in a sealed contained at, for example, a mail-processing center. The system includes filtration and vacuum subsystems cooperatively working to draw an air sample from the interior of the particulate containment system for evaluation by a biosensor or chemical analyzer to detect the presence of a contaminant. The vacuum subsystem includes a vacuum generator, flow meters, and pressure regulators to accommodate the varying volume within the particulate containment system. The filtration system includes an inlet filter and a high efficiency particle air filter (HEPA) filter. The inlet filter removes coarse impurities, such as dust and dirt, from the incoming air to improve sensor efficiency. The HEPA removes contaminants from the air sample prior to being released to the surrounding environment, thereby eliminating the possibility of spreading the contamination outside the particulate containment system.

Abstract: A jumbo mail drop box for isolating mail deposited therein which includes a drop box housing and a closable, removable chamber inside the drop box housing for receiving mail. The chamber is formed by a removable container having an opening in the top. The drop box has a plurality of mail transmitting chutes each having a deposit port at its upper end and an exit port at its lower end and arranged to receive mail through the deposit port and direct such mail into the closable chamber. There is an assembly for closing the opening in the removable container when desired to isolate the mail therein from the ambient atmosphere and permit removal of the container without exposing the ambient atmosphere to any hazardous material particles which may be on or in such mail. There is a removal door in the drop box housing to permit removal of the removable container therethrough.

Abstract: A device for limiting the size and shape of mail which may be deposited into a mail drop box. The drop box includes an enclosure having a deposit port at its upper end and of a predetermined size and shape, and a collection chamber below the deposit port. There is a pivotal door having at most substantially the same size and shape as the deposit port and closing the deposit port when the door is in a first, closed position and opening the deposit port when the door is in a second, open position. A plate is disposed in the enclosure between the deposit port and the collection chamber and of a substantially similar size and shape as the deposit port and having a restricted size opening and located to be exposed when the pivotal door in the open position to restrict the size of the deposit port to the restricted size opening.