Abstract: An electronic ballast control apparatus and method for fluorescent lamps includes applying a heating current through the filaments of the lamp, and delaying the application of arc current through the filaments and the gas for a predetermined time. This allows the filaments to heat up to a level capable of sustaining thermionic emission, thereby eliminating sputtering damage upon the application of the arc current.

Abstract: A square or circular apron formed of plastic coated disk-like sheet metal or fiber-metal reinforced synthetic material is bonded to a circular ring gasket having a surface conforming to the upper mating surface of an existing roof drain flange. Reinforcing rib depressions are formed in the apron outer region. The apron extends for a major radial extent beyond the periphery of the drain flange and with the gasket is clamped to the drain flange via existing bolt holes in the drain using stainless steel or bronze replacement bolts. Screws clamp the apron and the underlying roof membrane, which may be bonded to the apron to form a water tight seal, to the deck. A metal clamp ring may be used to clamp the apron and gasket to the drain flange. Various embodiments are disclosed.

Abstract: This invention provides a method for producing a mutant virus or viroid, or a mutant recombinant RNA molecule comprising a single stranded virus genome or a single stranded viroid genome, a circular virus genome or a circular viroid genome, or a segment of a virus genome or a segment of a viroid genome which comprises incubating a recombinant single-stranded RNA molecule comprising a recognition sequence for the binding of an RNA directed RNA polymerase, a sequence for the initiation of product strand synthesis by the polymerase and a heterologous sequence of interest derived from a different RNA molecule inserted at a specific site in the internal region of the recombinant molecule under appropriate selective conditions and for a sufficient period of time permitting the selection of a mutant population, the heterologous sequence of interest comprising the RNA of the single stranded virus genome or the single stranded viroid genome, the circular virus genome or the circular viroid genome or a segment of the v

Abstract: A circular thin metal or thermoplastic disc stress plate has an annular stiffening rim and groove and a central opening. Three equilateral and symmetrically oriented elongated nail-like members depend from the plate at the rib and groove inclined in diverging relation relative to a vertical axis normal to and central the plate on a conical surface of revolution. The members extend radially beyond the perimeter of the stress plate projected onto the members forming an annular attachment region to a cementitious substrate significantly greater than the area subtended by the stress plate. Two or more than three members may be used in the alternative. The nail-like members have conical tips which may be any shape and blunt. The members preferably are circular cylinder steel, may be other transverse sectional shapes, and are driven individually or simultaneously into the substrate either through holes in the plate or penetrate the plate material by a power operated nail driving tool.

Abstract: A device for and method of transmitting an encrypted message and an access field from a sender to a receiver, where a third party may intercept and process the transmission. The sender and receiver agree on a session key. The sender raises an element of a Galois Field to the session key; forms a temporary device unique key; encrypts the session key with the temporary device unique key; forms a temporary family key; encrypts an identifier of the sender and the encrypted session key using the temporary family key; encrypts a plaintext message using the session key; forms the access field by concatenating the element of a Galois Field raised to the session key to the encrypted version of the sender's identifier and the sender's encrypted session key; concatenates the ciphertext to the access field; and transmits the access field and the ciphertext to the receiver. The receiver may recover the plaintext from the sender's transmission.

Abstract: Weighing apparatus, which is suitable for weighing livestock. The apparatus s formed by a crate, which is open at at least one end and provides a platform on which an object to be weighed may be located, and a frame encompassing but spaced from said crate. The crate is slung by a single point from said weighing device mounted by the frame.Crate restraining means maintain said crate in a spaced relationship from the frame. The restraining means comprises a single flexible member and a single anchor point and tie on each end of said crate and a single mounting on opposite sides of said frame. The arrangement is such that in use when said flexible member is tensioned and anchored the crate is restrained from lateral movement against the frame without affecting vertical loading on the single point weighing device.