Abstract: A novel method of geophysical exploration is provided whereby shot points and receiver locations are positioned such that seismic data resulting therefrom can advantageously be processed employing 3-D processing techniques to obtain a better image of the earth's subsurface structure. In one embodiment, shot points, or alternatively, receiver locations are arranged along generally sawtooth or zig zag lines so that common midpoint bins of seismic signals include a generally uniform distribution of source-receiver pair azimuths. In another embodiment, both the shot points and receiver locations are arrayed along generally alternating, sawtooth or zig zag lines.

Abstract: Thermoplastic molding compositions are described which comprise an admixture of (a) an aromatic polycarbonate resin, (b) an olefinic polymer or copolymer and (c) a third component which is a copolymer of an olefin and an acrylate, methacrylate, acrylic acid or methacrylic acid. The presence of the third component enhances impact strength in thicker sections and improves weld line strength.

Abstract: A molding machine for dispensing at least two materials which, when combined, foam and cure within a mold thereby to form a plastic article. The dispensing is accomplished by displacing measured amounts of hydraulic fluid to a pair of chambers within each of which there is located a stainless steel bellows that is supplied with the respective material from a source thereof under pressure. When the displaced hydraulic fluid causes the bellows to collapse, the materials in the bellows are displaced therefrom into a mixing chamber in the form of high velocity jets and are mixed therein and the mixture is forced from the mixing chamber to the mold cavity to be filled. The bellows are then permitted to expand under the pressure of the material supplied thereto and the machine is ready for a further molding cycle.

Abstract: A method and apparatus for molding plastic materials, particularly foamed plastic materials, in which the materials are introduced into a mold cavity together with a foaming agent with the mold cavity being evacuated not later than immediately after the molding material is supplied thereto. The reduced pressure in the mold cavity causes the material to foam extremely quickly so as completely to fill the cavity while, at the same time, the mold is held closed by the pressure differential between the inside and outside thereof.