Abstract: A method and apparatus for preparing a continuous flow of castable composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at or below a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt.

Abstract: A method and kit, employing exo-sample nucleotides such as deoxyuridine, capable of altering the nucleic acid sequence present at the 3' or 5' end of a DNA or RNA molecule is provided. The method and kit can be used to achieve the selective amplification of nucleic acid molecules.

Abstract: This invention discloses a scheme for producing nucleic acid end products that are functionally or exactly identical to the starting products, thereby resulting in exponential amplification of a desired nucleic acid sequence. Specifically, sequences are cycled between RNA and DNA forms using the following basic steps: (1) a T7 RNA polymerase promoter is ligated onto a single-stranded DNA template; (2) T7 RNA polymerase makes many copies of RNA: (3) a complementary DNA is made from the RNA by extension of a primer by reverse transcriptase; and (4) the RNA template is removed by ribonuclease H. This amplification method is useful for purposes such as genetic research and diagnostic assays.

Abstract: A method for amplifying a nucleic acid molecule which employs a proto-promoter-containing nucleic acid molecule having a blocked 3' terminus. The invention also includes kits containing reagents for conducting the method.

Abstract: A method and apparatus for preparing cast composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt. Mixing is preferably accomplished with a dispersing impeller, or a dispersing impeller used with a sweeping impeller.

Abstract: A method is described for producing a corrosion and mechanical wear resistant coating on a metal surface to be protected. The method comprises (a) providing a rod or wire formed of a metal matrix composite comprising a metal matrix having distributed therein a finely divided solid filler material and (b) applying a coating of said metal matrix composite on said metal surface to be protected by means of a flame spraying or arc spraying process. This results in a coating of improved adhesion and low porosity.

Abstract: A method for preparing cast composite materials of nonmetallic carbide particles in a metallic matrix, wherein the particles are roasted and then mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The particles are roasted in air or other source of oxygen to remove the carbon from the near-surface region of the particles and to produce an oxide surface diffusion barrier, resulting in a reduction of carbide formation in the molten matrix. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt.

Abstract: A method and apparatus for preparing cast composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt. Mixing is preferably accomplished with a dispersing impeller, or a dispersing impeller used with a sweeping impeller.

Abstract: Silicon carbide particulate reinforced aluminum alloy matrix composites are formed using techniques which include agitation of a melt of aluminum alloy, containing magnesium, and silicon carbide particulates in a manner whereby the silicon carbide particles are maintained, during agitation, within the body of the melt; the agitation, which involves shearing or wiping of the particles in the liquid, is carried out under vacuum; and may involve incorporation into the melt of an additional amount of magnesium such that that amount compensates for the amount of magnesium which segregates to the carbide surfaces, and is sufficient to effect strengthening of the resulting composite. Aluminum alloy matrix composites, containing copper, are produced using similar agitation and mixing procedures, with the copper being incorporated in such a way as to discourage reaction between the copper and SiC particles.