A surgical tissue macerating and removal tool is disclosed wherein a rotating member having a cutting tip is utilized. When the instrument is to be used in an eye, a treatment fluid is supplied to the operative site and a first pump is provided to evacuate macerated material and treatment fluid from the eye. A second pump means is provided on the rotating member to provide a counter flow of treatment fluid into the space between the rotating member and the support tube. The second pump may provide additional support for the rotating member. Means is also provided for axially positioning rotating member to increase or decrease cutting action. CATALYTIC TRIMERIZATION OF AROMATIC NITRILES AND TRIARYL-S-TRIAZINE RING CROSS-LINKED HIGH TEMPERATURE RESISTANT POLYMERS AND COPOLYMERS MADE THEREBY NASA Case No. LEW-12053-1 Canada, France, Great Britain, Address inquiries to: 21000 Brookpark Road Corresponding to U.S. Patent No. 4,061,856 Filed 10-10-74 Prior trimerization methods are unsuitable for processing the aromatic nitrile-modified (terminated and/or appended) condensationtype prepolymers into s-triazine ring cross-linked high temperature resistant matriz resins for fiber reinforced composites. With this invention, aromatic nitrile such as p-cyanobenzoic acid and its esters, etc. can be directly trimerized to their corresponding triaryl-s-triazines at moderate temperature and pressure. Also, with this invention, the norborene groups on the addition-type polyimides are replaced by aromatic nitrile groups, or part of the monomeric reactants (aromatic diamines and tetracarboxylic acid dianhydride or their derivatives) of those soluble high molecular weight polyimides having relatively low thermal stability were replaced by nitrile appended aromatic diamines and aromatic tetracarboxylic acid dianhydrides or their derivatives. These terminating and/or appending aromatic nitrile groups are then catalytically trimerized to produce new triaryl-s-trazine ring containing or cross-linked polyimides which possess the outstanding thermal stability of both polyimides and aryl-s-triazines for continuous use at temperatures above 315°C. The present invention relates generally to a method and apparatus for splitting a communication laser beam into a pair of beams in a laser transmitter and for combining a carrier beam with a second beam to produce a pair of combined beams at a laser receiver. The invention is presently used in experimental laser system transmitters and receivers being developed for satellite use. This invention relates to a method and apparatus for quantitatively determining the handle of fabrics and other flexible materials. Handle is a fabric term used to refer to the qualities of compressibilities, deapability, foldability, stiffness, pliability, etc., possessed by all fabrics and similar flexible materials. A material with good handle is usually soft to the touch, easily compressed and easily folded, whereas a material possessing poor handle qualities is stiff, crisp and boardy. The present invention discloses a numerical quantity termed handle modulus (expressed in dimensions of force per unit area) by which the handle of a given flexible material sample may be directly compared with the handle of other materials which need not be presently available for comparison. In the past handle determination was subjective in whole or part and required direct subjective comparison between samples. PSEUDO CONTINUOUS WAVE INSTRUMENT NASA Case No. LAR-12260-1 Great Britain, Japan, Address inquiries to: Corresponding to U.S. Patent No. 4,117,731 Filed 12-8-77 Issued 10-8-78 A device for measuring acoustic properties and their changes in a sample. A variable frequency source is applied to the sample by means of a transducer to produce sound waves within the sample. The variable frequency source is periodically interrupted for a short duration. Means are connected to the transducer for receiving the resulting acoustic signals during the interruptions for producing a control signal indicative of a difference in the frequency of the output of the variable frequency source and the frequency of a mechanical resonant peak in the sample. The control signal is applied to the variable frequency source to maintain its output frequency at the frequency of the mechanical resonant peak. The change in frequency of the variable frequency source is indicative of the shift in frequency of the mechanical resonant peak and the amplitude of the acoustic signals is indicative of the attenuation of the acoustic signals in the sample. |