Abstract: A process for the preparation of tripeptides of the general formula IU-A-B-C-OH Iin which U denotes hydrogen or a urethane protective group and A, B and C denote amino acids, by reaction of a compound of the general formula IIU'-B-OH IIin which U' is a urethane protective group which can be eliminated by hydrogenolysis, with a compound of the general formula IIIH-C-OR IIIin which R denotes alkyl, by the PPA method, elimination of U', and reacting the resulting compound of the formula IVH-B-C-OR IVwith a compound of the formula VU-A-OH Vin the presence of propylphosphonic anhydride, and finally eliminating R enzymatically.

Abstract: This invention relates to a process for the isolation and purification of polyarylene sulphides, preferably polyphenylene sulphides, from their reaction mixture. The process requires no organic solvents for the purification (washing) of the polymer.

Abstract: A circuit arrangement for channel-specific processing of a multi-channel input signal which may consist of two types of encoded signals, a first type wherein all channel signals are encoded by a bit-oriented method (e.g., delta modulation) and a second type wherein all channel signals are encoded by a character-oriented method (e.g., PCM). An interface process (SSP), to which the input signal is applied, is coupled to a bidirectional interface (BIS) for signals of the first type and which is controllable by means of write and read addresses, and is also coupled to at least two such bidirectionally controllable interfaces (BI0, BI1, . . . BI7) for signals of the second type. The latter interfaces are respectively coupled to respective transcoder processors (AP0, AP1, . . . AP7). One or more data outputs of the interface (BIS) for signals of the first type are respectively coupled to respective ones of the transcoder processors (AP0, AP1, . . . AP7).

Abstract: An impact pad for eliminating surface turbulence in a continuous caster tundish, the impact pad having a base for receiving an incoming ladle stream, and one or more sidewalls extending in an upward direction along the periphery of the base. Each upward extending sidewall includes an inner surface having an undercut portion facing the incoming ladle stream. And, each undercut portion extends along the length of the inner surface, and comprises a shaped surface for receiving and reversing the direction of a fluid flow generated by the incoming ladle stream.

Abstract: A system for mounting VLSI devices on a substrate is disclosed, offering a high contact density. Each package consists of a semiconductor device having protruding elongated contact pin (2) on its surface and a wiring substrate having a cavity (3) on its surface. The cavities are filed with a conductive material (7) of a low melting point composition and sealed with a thin non-conductive foil (4). During packaging, the contact pins are made to penetrate the foil, and extend into the conductive alloy, thus making electrical contact therewith. To ease the penetration of the foil, the contact pins could be set into oscillating motion by means of an ultrasonic generator.

Abstract: The present invention relates to water-dispersible polyetherester-modified polyurethane ionomers containing 10 to 100 milliequivalents of ionic, preferably cationic, groups per 100 g of ionomer; 2 to 40% by weight of polyetherester groups; and 1 to 35% by weight of ethylene oxide units, in which the percentages are based on the weight of the polyetherester-modified polyurethane ionomer.The present invention also relates to a process for the preparation of these polyetherester-modified polyurethane ionomers and to aqueous compositions containing these polyetherester-modified polyurethane ionomers and polymers containing perfluoralkyl groups.

Abstract: A supply magazine has a drawer-shaped, upwardly open box for introducing a sheet film stack in a light-tight envelope and for withdrawing individual sheet films after removal of the envelope, a cover part movable relative to the box, a unit for winding the envelope in a closed condition of the magazine. The cover part is formed as a flat parallelepiped which is open at its front small side and such that the box which is open at its upper side can be moved in and out of the cover part, a locking mechanism operates for locking the cover part and the box when the box is moved in. A lockable and swingable flap cover is provided on a flat side of the cover part corresponding to the upper side of the box so that when the box is moved in the cover part a sheet film stack can be inserted in the box through the flap cover.

Abstract: A daylight loading film sheet package has a stack of film sheets enclosed within a wrapper having front and rear panels covering the front and rear faces of the film stack and projecting side extensions on at least three sides of the panels which are folded into contacting relation and adhered together in close proximity to the corresponding sides of the stack to cover such stack sides. One of the wrapper panels has a sheet-dispensing opening therein with one edge adjacent one stack side which is generally coextensive in length with that stack side, such opening extending from the edge into the panel to permit an outermost film sheet to be accessed and withdrawn from the stack therethrough.

Abstract: The invention relates to linear and branched poly-p-arylene sulfides (PAS), preferably poly-p-phenylene sulfides (PPS), which have an extremely low proportion of defect or foreign structures, to a process for their production and to their use for the production of molded articles.

Abstract: The present invention is directed to a diisocyanate which corresponds to the formula ##STR1## The present invention is also directed to the preparation of this diisocyanate and to its use for the production of polyisocyanate polyaddition products.

Abstract: The X-ray sheet film cassette has a top part hinged to a base part. The bottom of the base part is provided with a frame enclosing a film supporting plate through which the radiation is transmitted. The supporting plate has a laminated structure including two face plates of thermoplastically bonded carbon fibers and a comparatively thicker intermediate plate of a synthetic hard foam rubber sandwiched between the face plates and being glued thereto. The face plates are considerably thinner than the intermediate plate in the laminated supporting plate of the present invention.

Abstract: The compressor cascade comprises a plurality of tandem-connected membrane pumps, each of the pumps having a plurality of stroke chambers whose volumes decrease in the direction of the fluid flow through the pumps. Each chamber has several parallel-connected input/output channels for interconnecting the individual membrane pumps and a check valve in each input/output channel for forcing the fluid in a specified direction. By electrostatic attraction forces, the membranes in the pumps are energized synchronously to resonance oscillations of the same frequency and deflection, building up the necessary operating pressure as the fluid is moved from the stroke chamber of one membrane pump into the smaller volume stroke chamber of the next succeeding membrane pump. The movement of the fluid through the membrane pumps of the compressor cascade leads to its compression, and the pressure at the end of the cascade is related to the reduction in volume of each succeeding stroke chamber.

Abstract: A machine tool has a pair of rotary spindles which support opposite ends of workpiece to be machined. At least one of the spindles is driven and a ring having a plurality of arms is coaxially secured to this spindle for rotation therewith. The arms entrain an annular member which is essentially coaxial with the spindles and is provided with threads. An annular guide plate which is again essentially coaxial with the spindles supports a plurality of clamping jaws for movement radially of the spindles. The clamping jaws are provided with threads which mesh with the threads of the annular member so that rotation of the latter can cause movement of the clamping jaws. A plurality of rocker arms is mounted on the machine tool for pivotal movement between an inoperative position and an operative position in which the rocker arms engage the periphery of the guide plate to prevent rotation thereof.

Abstract: Disclosed is a tundish apparatus for holding and filtering molten metal, such as steel, prior to the molten metal being continuously cast. An enclosure around the discharge orifice of the tundish accommodates a ceramic filter medium. The enclosure has a removable cover plate to allow continuous discharge of the molten metal in the event the filter medium becomes clogged and to allow access to the tundish nozzle.

Abstract: The invention relates to blends of polyarylene sulfides, epoxides, glass fibers, optionally anhydride-containing polymers and optionally other additives. They are distinguished by good mechanical properties.

Abstract: This invention relates to a process for the production of high molecular weight, optionally branched polyarylene sulfides having a reduced content of extractable oligomeric constituents. They are prepared by reaction of alkali sulfides and/or alkali hydrogen sulfides with aromatic dihalogen compounds in a polar organic solvent.

Abstract: The invention relates to a process for the production of high molecular weight, optionally branched polyarylene sulfides having a low content of organically bound halogen. They are prepared by reaction of alkali sulfides and/or alkali hydrogen sulfides with aromatic dihalogen compounds in a polar organic solvent.

Abstract: In the conversion of trichloroethene and tetrachloroethene into dichloroacetyl chloride (DAC) or trichloroacetyl chloride (TAC) by means of oxygen, the reaction mixture is passed several times as a thin film through the reaction zone. The reaction time for achieving a certain conversion is in this way reduced.In the preparation of DAC, a constant content of acid chloride is established in the reaction mixture by removing some of the mixture and working this up by distillation, while the circulating reaction mixture is simultaneously topped up with fresh trichloroethene.In this way, side reactions are suppressed and the amount of by-products is reduced.

Abstract: The invention relates to a process for the production of linear, unbranched polyarylene sulfides from aromatic dichlorine compounds and alkali sulfides in tetra-alkylated, cyclic ureas as the reaction medium.

Abstract: Rhenium-oxo complexes withoctaethyl porphyrin or5,10,15,20-tetraphenyl porphyrins or5,10,15,20-tetra(4-pyridyl)-porphyrins as ligandswhich optionally carry an anion on the central atom. Methods of preparing the complexes are also disclosed.