Abstract:
Production of hollow carbon fibers and hollow carbon particles includes baking and carbonization of polymer particles having a specified volume after deformation. A metal-deposited carbon fiber with metal deposited inside and/or outside the hollow carbon fiber is applicable to electron discharge devices. The thickness and crystallinity of the graphite layer can be freely controlled. Since almost no by-product is generated, separation and refining using a solvent is not required. A hollow carbon particle of desired shape can be produced at a high yield rate. The hollow carbon fiber represented by a carbon nano-tube can be controlled in such a way that a low resistance and uniform shape are provided so that there is an increase in the amount of electrons discharged from the hollow carbon fiber. Use of this hollow carbon fiber as an electron discharge source provides an excellent electron discharge device characterized by stable pixels.
Abstract:
A fluorine-containing polyimide having a low dielectric constant, low water absorption and excellent heat resistance and moisture resistance and a precursor thereof such as a fluorine-containing polyamide-acid, can be prepared by reacting an acid anhydride with an aromatic diamine having perfluoroalkyl group.
Abstract:
A ball valve is provided which comprises a valve body formed from a tubular member with a cylindrical hole extending therethrough, a stem having one end thereof projecting into the hole, and a ball fixed to an end of the stem. The ball has a circular bore extending diametrically therethrough, wherein the ball is spherical in shape with removed chordal segments corresponding to the bore. A seat carrier is inserted in the hole, the seat carrier having one end adjacent the ball, a connecting sleeve contacts the seat carrier at the other end thereof opposite the end adjacent the ball, and a union nut couples the connecting sleeve to the valve body. Diametrically opposed projections are provided on the inner surface of the valve body, the projections extending into the hole, recesses formed on the side of the seat carrier adjacent the one end thereof, and diametrically opposed grooves are formed in the side of the seat carrier adjacent the recesses. The grooves extend in the circumferential direction from the adjacent recesses. When the seat carrier is inserted into the valve body and rotated therein, the projections on the valve body engage the grooves in the seat carrier to thereby hold the seat carrier in the valve body. Further, a flange is formed on the other end of the seat carrier wherein one of the flange and valve body includes at least one projection and the other of the flange and valve body includes at least one cavity. The projection is engaged in the cavity to prevent the rotation of the seat carrier with respect to the valve body.
Abstract:
A movable vane compressor has a cylinder profile such as to reduce a pulsation of the driving torque for movable vane. This cylinder profile includes in series a region where the amount of vane projection increases; a region where the vane retracting speed increases; a region where the vane retracting speed decreases; a region where the vane retracting speed increases; a region where the vane retracting speed decreases; a region where the vane retracting speed increases; and a region where the vane retracting speed decreases.
Abstract:
A ball valve in which, even when a connecting sleeve is removed by loosening the associated union nut, the ball and annular seals of the valve will not blow out of the valve body under fluid pressure. A ball with an integral spindle is arranged in the valve body in such a manner as to be able to open and close a fluid passage therein. A seat is formed in the valve body and a part of the surface of the ball on the side thereof opposite the side where the spindle is provided and around a rotational axis of the spindle is in surface contact with the seat to thereby pivotally support the ball. Annular seals are provided in the fluid passage abutting against the ball from both sides to pivotally support the ball with the annular seals being urged towards the ball by seal carriers.
Abstract:
Decorative moldings with non-uniform sections made of thermoplastic resin are produced by remolding. The material to be remolded is formed by cutting an extruded rod or combining an extruded rod with other parts and being placed in a mold. The material in the mold is heated and partially fused by high frequency dielectric heating. Then the fused portion of the material is cooled in the mold so that the material is partially remolded.
Abstract:
A hot air blast welding apparatus for welding works of thermoplastic materials having different softening temperatures. The apparatus includes a nozzle having nozzle openings for applying hot blasts of air to respective ones of the works. The nozzle is so constructed that it applies air blasts of different temperatures or different flow rates to the works so that the works are brought substantially simultaneously to softening points.