Abstract: A process for producing printed circuit boards having metallic conductor structures embedded in the insulating substrate and whose front and back sides are conductively connected by means of plated through holes. The first steps of the process comprise producing a matrix on an epoxy resin substrate consisting of a lift-off layer, an aluminum barrier layer and a positive photoresist layer. A negative image of the desired conductor pattern is then generated in the photoresist layer using conventional photolithographic techniques. The negative image is etched into the barrier layer and the lift-off layer such that an undercut occurs under the barrier layer. Subsequently, vertical trenches are etched into the epoxy resin substrate. After drilling of the through holes, an activating layer of copper is deposited by means of magnetic field enhanced cathode sputtering on the surfaces of the trenches, the through holes and the barrier layer.

Abstract: After cleaning and removal of oxidic layers, the defective copper conductors are completely etched off the surface of the external planes of a multilayer circuit board, and the copper on the walls of the plated through holes is etched at an etching rate continuously decreasing toward the center of the hole walls. Subsequently, an activating layer of copper is applied on the surface of the substrate and on the adjacent parts of the surface of the hole walls. Copper conductors defined by a photoresist mask in a known manner, are deposited on the surface of the activating layer following the additive technique, the copper is deposited on the entire surface of the hole walls. As the maximum etching depth of the copper on the hole wall is approximately 0.2 mm maximum, and as the activating layer is applied up to a depth of approximately 1.2 mm a perfect copper overlap on the walls is ensured.

Abstract: The relative concentrations of solvent and solute in a solution are altered by a system which includes a cell having chambers separated by a membrane and a means for creating a pressure differential across the membrane. A solution moves through an inlet means around the system and countercurrent and reflux flow and outlet means. The cell may be formed of modular units in such a way as to effect a tapered configuration so that the flow rate is homogeneous around the system.

Abstract: There is described a method of closing ends of silicon tubular bodies in which the tube end to be closed is dipped into melt of silicon maintained at substantially the melting temperature of silicon until the end of the tube is heated to the melting point and then withdrawing the tube from the melt with melt temperature sufficiently low to cause freezing of molten silicon at tube end and at temperature and speed sufficient to cause decreasing diameter of the freezing silicon until the desired diameter reduction or closure is obtained and then breaking contact with the melt. Additionally, surface portions may be machined after withdrawal from the melt to allow connections to be made.

Abstract: A self-sealing valve useful in a fluid fillable article, such as a mammary prosthesis, includes first and second planar members which are bonded together so as to leave an elongated unbonded portion therebetween. Openings are formed for communication between the unbonded portion and the inside and outside of a fluid fillable article containing the valve. The openings are offset from one another so that the openings and the unbonded portion form a normally open channel through the valve. At least one planar member is sufficiently flexible to close the channel responsive to pressure from within a fluid fillable member containing the valve.

Abstract: In a through-the-cannula catheter placement system, a catheter is used which comprises a body portion and a tip portion at one end of the body portion. The body portion has a double-wall structure. The outer wall is a tube of pliable, nonthrombogenic material. The inner wall is a reinforcing tube of a material having sufficient resilience to avoid collapse during use. The tip portion is also made of a pliable nonthrombogenic material. The tip may be an extension of the outer wall.

Abstract: A surgically implantable mammary prosthesis comprises a sac containing a filler material. The filler material is present in an amount sufficient to give the sac a relatively low profile shape and a pliant, responsive nature. The prosthesis includes a restraining means for resisting the tendancy of tissue to form the prosthesis into a sphere. The restraining means functions reactive to tissue pressure and does not substantially reduce the pliant, responsive nature of the prosthesis.

Abstract: A contact lens of a preselected mass has an optical zone and at least one peripheral zone. The optical zone has a shape and thickness sufficient to result in a desired optical correction. At least one peripheral zone has a thickness selected to correspond with that of the optical zone so as to result in the lens having the preselected mass. In a preferred embodiment, the lens has an optical zone, an intermediate peripheral zone and an outer peripheral zone. The intermediate peripheral zone has a thickness which is varied to correspond with that of the optical zone and the outer peripheral zone has parallel carriers. The preferred embodiment may have an inner surface shaped so that the radius of curvature of the optical zone is substantially equal to that of the cornea at its optical centerline, the peripheral curves have centers of curvature offset from the centerline of the optical zone and the curves are tangent where they meet.

Abstract: The inner surface of a semi-scleral contact lens is shaped relative to the topography of an individual eyeball to achieve central contact and edge contact with tearfilm clearance therebetween. The lens has improved centering properties. The lens includes an optical zone which is the spherical equivalent of the radius of curvature of the cornea at its optical centerline and the corneal dimensional diameter. The optical zone has a sagittal depth which is dependent on the topography of the cornea. The lens also includes a conoid section which is tangent to the edge of the optical zone and which extends from the edge of the optical zone to a selected point over the limbus. A peripheral curve having an individual radius of curvature extends from the selected point to the edge of the lens.

Abstract: A contact lens has an improved interior surface which includes an optical zone and peripheral zone. The optical zone has a radius of curvature similar to that of the cornea of the eye to be fitted. The peripheral zone defines an arc which is substantially tangent to the optical zone at its edge and which intersects the curved line defined by the selected diameter of the lens at the selected sagittal depth. The lens can be formed from a hard or flexible material and can be made by a lathe turning or by molding.

Abstract: In accordance with a preferred embodiment of this invention there is provided a method and apparatus for coating a wire or cable with a thermosetting polymer formed from a "liquid polymer" system such as a two-component polysiloxane. This system may be characterized as having two components each having a low viscosity and which when mixed react quickly to form the cross-linked polysiloxane rubber.

Abstract: A surgically implantable device for expanding skin and mucous tissue comprises a partially collapsed sealed envelope formed from a material which is permeable to extracellular body fluid. The envelope contains a material which establishes an osmotic potential across the envelope wall. Body fluid crosses the membrane to fill the envelope. As the envelope fills it expands the adjacent tissue. In use, the partially collapsed envelope is surgically implanted under the tissue to be expanded and is allowed to absorb fluid whereby expansion of the bag and subsequent tissue expansion is accomplished. A variety of surgical procedures using the expanded tissue are possible.

Abstract: A hydrophilic, water-swellable, crosslinked gel is produced by copolymerizing a water soluble vinylic constituent in aqueous solution with olefinic hydrolyzable silanes which contain low molecular weight alkoxy groups. Copolymerization is via the unsaturated groups and crosslinking is by condensation reactions. The copolymer is swellable to a finite extent or to an infinite extent depending upon the water/vinylic monomer volume ratio and upon the vinylic monomer:silane mole ratio. Non-toxic embodiments of the gel are especially useful as prosthesis fillers. Such gels can be used to fill the prosthesis before implantation or the prosthesis can be swollen with an aqueous solution after implantation.

Abstract: A charge pattern of a single polarity and having at least three different levels of potential is developed in two colors by utilizing relatively negatively charged toner particles of one color and relatively positively charged toner particles of a second color.

Abstract: Waveguides having light propagating therethrough are positioned between a common electrode and individual electrodes arranged along a charge-coupled device. The waveguides are of a type which modulate the propagating light responsive to an electric field. The charge-coupled device is activated to place charges at selected ones of the individual electrodes, creating a field across the waveguide by which light propagating through the waveguide is modulated.

Abstract: A multipurpose pallet system is provided which includes a deck means attachable either to a base member or a plurality of base members by shear pin and spring connections providing a yieldable break-away connection. Openings in the deck means receive pallet posts which are useful for supporting side members and for stacking the pallets.

Abstract: An electrical information or latent image storage system using a storage element which comprises a layer of substantially electrically insulating material having a layer of electrically photosensitive particulate material embedded therein, with a layer of semiconductor material overcoating one surface of the layer of insulating material, and an electrode on the opposite surface of the layer of insulating material. Information in the form of localized electrical charges of an electrical latent image is placed on the element by electrical or photo-electrical means, the information can be retrieved by scanning the element using an electrode-pair grid pattern, an electron beam, or other suitable means, and the retrieved information may be used, for example, through a computer, or reconstructed into a visible image corresponding to a latent image.

Abstract: Amplification of optical signals propagating through a first waveguide is achieved by modulation of high intensity light propagating through an elastomeric waveguide responsive to said signals, the modulation of the high intensity light being accomplished by an apparatus including a photodiode for registering the modulation of the optical signals and an electrode arrangement for causing corresponding light-modulating deformation of the elastomeric waveguide, the circuitry between photodiode and the electrode arrangement including a resistor and a D.C. power source.

Abstract: An imaging apparatus in which an electrostatic latent image is developed on an insulating web at a development station after which the web is transported to a platen capable of supporting a receiving surface. The web is transported from the development location to the platen in a plane parallel to the axis of the platen. The image is then transferred to a receiving surface supported by the platen. The imaging, development and transfer are controlled by a control logic circuitry.

Abstract: Graphic reproductions are achieved by the image-wise modification of the triboelectric charging capability of a surface followed by the triboelectric charging of the modified surface to produce a charge pattern corresponding to an image. The charge pattern may be developed with finely divided colored electroscopic particles and the resulting colored image either fixed on the surface of the insulating member or transferred to a receiving surface and fixed thereon.