摘要:
The invention relates to a surgical implant that provides an artificial diarthroidal-like joint, suitable for use in replacing any joint, but particularly suitable for use as an intervertebral disc endoprosthesis. The invention contains two rigid opposing shells, each having an outer surface adapted to engage the surfaces of the bones of a joint in such a way that the shells are immobilized by friction between their outer surfaces and the surfaces of the bone. These outer surfaces are sufficiently rough that large frictional forces strongly resist any slippage between the outer surface and the bone surfaces in the joint. They may be convex, and when inserted into a milled concavity, are immediately mechanically stable. Desirably, the outer surfaces of the shells are adapted to allow for bony ingrowth, which further stabilizes the shells in place. The inner surfaces of the shells are relatively smooth, and adapted to slide easily across a portion of the outer surface of a central body disposed between the shells. The central body has a shape that cooperates with the shape of the inner surface of the shell so as to provide a range of motion similar to that provided by a healthy joint. A flexible sheath extends between edges of the opposing shells. The inner surface of this sheath, together with the inner surfaces of the rigid shells, defines a cavity encasing the central body. At least a portion of this cavity is filled with a fluid lubricant, further decreasing the frictional force between inner surfaces of the shell and the surface of the central body.
摘要:
The invention relates to a surgical implant that provides an artificial diarthroidal-like joint, suitable for use in replacing any joint, but particularly suitable for use as an intervertebral disc endoprosthesis. The invention contains two rigid opposing shells, each having an outer surface adapted to engage the surfaces of the bones of a joint in such a way that the shells are immobilized by friction between their outer surfaces and the surfaces of the bone. These outer surfaces are sufficiently rough that large frictional forces strongly resist any slippage between the outer surface and the bone surfaces in the joint. They may be convex, and when inserted into a milled concavity, are immediately mechanically stable. Desirably, the outer surfaces of the shells are adapted to allow for bony ingrowth, which further stabilizes the shells in place. The inner surfaces of the shells are relatively smooth, and adapted to slide easily across a portion of the outer surface of a central body disposed between the shells. The central body has a shape that cooperates with the shape of the inner surface of the shell so as to provide a range of motion similar to that provided by a healthy joint. A flexible sheath extends between edges of the opposing shells. The inner surface of this sheath, together with the inner surfaces of the rigid shells, defines a cavity encasing the central body. At least a portion of this cavity is filled with a fluid lubricant, further decreasing the frictional force between inner surfaces of the shell and the surface of the central body.
摘要:
A metallurgical processing system for economically recovering metal values, such as columbium, tantalum, thorium, and uranium from dilute source solids, such as digestion sludges, by a series of steps including:1) slurrying the source solids with dilute hydrofluoric acid to produce a solid phase and a liquid phase containing dissolved tantalum and columbium, then extracting tantalum and/or columbium from the liquid phase by means of a liquid ion-exchange process and then, additionally;2) roasting the solid phase with sulfuric acid to recover and recycle hydrofluoric acid, leaching the roasted solids with dilute sulfuric acid to produce a disposable solid phase and a liquid phase containing thorium and uranium, and extracting thorium and uranium from the liquid phase by means of a liquid-liquid amine extraction process.
摘要:
A melted polymer of hydroxyacetic acid with itself or with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties is subjected to high shear and injected into an organic liquid which is inert to the polymer to form an organic liquid dispersion of very fine polymer particles. In one aspect the melted polymer is combined with the organic liquid and the combination is thereafter subjected to high shear to form the fine particle polymer dispersion. A dispersion agent may also be used to aid in dispersing the particles. The dispersion is used for fluid loss control and gel breaking in subterranean formations.
摘要:
An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the method comprises adding water containing an effective amount of a combination of an alkaryl sulfonate having a molecular weight of 415 to 470 and a C.sub.1 -C.sub.4 alcohol.
摘要:
Stoppage of gas-water streams due to the formation of gas hydrates is prevented by incorporating in such streams a surface active agent which inhibits the formation of gas hydrates and/or the agglomeration of hydrate crystallites into large crystalline masses.
摘要:
A fluid separating apparatus in which an inlet is disposed in the upper portion of a substantially vertically oriented cylindrical housing for receiving a mixture of liquid and vapor. The mixture is separated in the housing by the application of centrifugal forces to the mixture and the liquid exits from the lower portion of the housing and the vapor rises and exits from the upper portion of the housing.
摘要:
An improved anionic waterflood additive is prepared by partially chlorinating a normal alkane having about 10 to about 18 carbon atoms to about 2 to about 15 weight percent chlorine content, employing the chlorinated alkane to alkylate an aromatic hydrocarbon, such as benzene; sulfonating the thus formed alkylate or a fraction thereof to form a sulfonic acid; converting the sulfonic acid to a sulfonate by reacting with a base component, such as an alkali metal hydroxide, ammonium hydroxide, or an alkali metal carbonate; and overbasing the sulfonate by admixing with an excess of base component such that the ratio: "weight of excess base component/weight of sulfonate" is about 0.03 to about 3.0. The anionic waterflood additive is injected into a petroliferous formation, the formation is waterflooded, and oil is recovered.
摘要:
An improved anionic overbased waterflood additive comprises a base component, a first sulfonate component derived from an alkylation reaction product employing a branched-chain alkene as the alkylating agent, and a second sulfonate component derived from an alkylation reaction product employing a partially chlorinated normal alkane as the alkylating agent, wherein the base component is present in the weight ratio range of 3/100 to 300/100, base component to total sulfonate, and wherein the weight ratio of the first sulfonate component to the second sulfonate component is in the range of 1/9 to 9/1. The overbased waterflood additive may be formed prior to injection into a petroliferous formation or may be formed in situ by first injecting the total sulfonate followed by the base component.