Abstract: Various methods and devices are provided for allowing multiple surgical instruments to be inserted into sealing elements of a single surgical access device. The sealing elements can be movable along predefined pathways within the device to allow surgical instruments inserted through the sealing elements to be moved laterally, rotationally, angularly, and vertically relative to a central longitudinal axis of the device for ease of manipulation within a patient's body while maintaining insufflation.

Abstract: This invention relates to an improved process for the recovery and regeneration of nitric acid from spent acid obtained from the mixed acid nitration of aromatic compounds. In that process a mixed acid of sulfuric acid and nitric acid is contacted with an aromatic composition at a temperature and pressure sufficient for producing a nitroaromatic composition and a spent acid containing unreacted nitric acid, sulfuric acid and solubilized nitroaromatic compounds in said spent acid. The improvement comprises initially heating the spent acid to a temperature of from about 120.degree. to 200.degree. C. for a time sufficient to convert said nitroaromatics in said spent acid to a nitroaromatic composition having a boiling point greater than 300.degree. C. at atmospheric pressure and then flash distilling the hot spent acid containing nitroaromatics compositions at a pressure from about 5 to 15 psia and temperature of 150.degree. to 200.degree. C.

Abstract: This invention relates to a process for removing trinitrocresols and picric acid contaminants from a wastewater stream generated in the production of nitroaromatics, particularly dinitrotoluene, by the mixed acid technique. The process involves contacting the crude dinitrotoluene generated by the mixed acid technique with an alkaline medium to generate an alkaline wash water containing water soluble nitrocresols and picric acid therein. This wastewater then, is separated from the organic component or may be recycled for contact with further quantities of crude dinitrotoluene product from the reactor. When the concentration of the water soluble salts of trinitrocresols and picric acid is of sufficient concentration, the wash water is treated with aqueous acid in sufficient proportion to reduce the pH to a level from 3-4.

Abstract: Low density conductive carbon black agglomerated particles are finely divided to a particle size below 0.044 millimeter and added in a portionwise manner to a PVC resin in a closed system. The process ensures a uniform dispersion of the carbon black into the PVC resin and uniform bulk and surface properties of articles molded from the resultant resin.

Abstract: An improved molding composition having a bulk resistivity below about 500 ohm-cm at 900 megahertz for compression molding video discs comprising sufficient conductive carbon black particles to obtain the desired conductivity, from about 1.5 to 4 percent by weight of stabilizers, from about 1 to 3 percent by weight of at least two lubricants, up to 10 percent by weight of plasticizers and processing aids, the remainder being a polyvinylchloride based resin, with the proviso that not more than about 5 percent by weight of liquid additives are present in said molding composition. Video discs molded from said composition have improved dimensional stability.

Abstract: A vinyl chloride based injection molding composition comprises a vinyl chloride-propylene copolymer, a mercapto tin stabilizer, an acrylic processing aid and an ester wax lubricant. This composition has excellent flow characteristics and can form molded articles with sub-micron dimensional details and excellent surface characteristics.