Abstract: A method of eradicating plants on an inaccessible terrain by selecting hollow balls formed by a frangible membrane, filling such balls with respective charges of herbicide fluid of the type to which such plants are susceptible to provide a supply of such charged balls. Selecting a repeater ball firing gun of the type incorporating a mechanism having sufficient propulsion to transmit a certain minimum muzzle velocity to such balls in a repetitive manner, transporting such gun by helicopter to hover over such terrain. Shooting a quantity of such balls at each plant from a range sufficiently close to cause the skins of such balls to be ruptured upon impact to thereby splash herbicide on the respective plants.

Abstract: Magnetic tape reels, using file protect rings disposed within an annular channel concentric with the spindle opening within the tape reel, can be provided with a unique, access coding by defining a first plurality of recesses or projections on the bottom surface of the annular channel and a corresponding and mating second plurality of projections or recesses on the bottom and opposing surface of the file protect ring. The pattern of recesses, projections or both defined within the annular channel and on the bottom surface of the file protect ring uniquely associates each file protect ring with each tape reel such that a given ring will fit flushly with only one reel. A conventional electromechanical actuator senses whether or not the file protect ring is appropriately and flushly disposed within the channel, thereby preventing erasure or overwriting on the tape.

Abstract: There is disclosed a security seal apparatus for securing information recorded on a recording medium such as a floppy disc or recording tape which incorporates an aperture therein. The security seal apparatus includes a circular rigid pad projecting beyond the edges of such aperture and formed centrally with a post for projecting through such aperture. The post is formed on its free extremity with an enlarged-in-diameter conical lock head having its base of a cross-section less than the cross-section of the aperture. A fastener plate is provided with a central opening having a diameter slightly less than the base of such conical lock head so that such fastener plate may be pressed onto such lock head causing the base of the conical lock to be compressed radially inwardly whereby the lock will pass through such opening and expand radially outwardly to overlie the peripheral edges of such opening and lock the fastener in position.