Abstract: A cryosurgical system comprises a compressor unit and a probe assembly. A secondary refrigerant stream from the compressor unit pre-cools a heat exchanger within the probe assembly in a standby mode of operation. After the heat exchange is pre-cooled, a primary refrigerant stream can be passed through the cooled heat exchanger and thereafter expanded within a tissue-contacting portion of the probe assembly to achieve very low temperatures, typically minus 100° C. or lower. After cooling, the refrigerant stream may be passed through the probe assembly with no or partial expansion to warm the tissue-contacting surface of the probe. A probe sheath can be used to provide sterility.

Abstract: A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant is injected into a cyclone chamber ?32! through the inlet tube ?34!. While the liquid drains down a conical section ?36! and out through a liquid line ?38!, the vapor phase moves up into a packing of metal platelets ?42! which is, in a particular embodiment, cooled by a returning stream of cold vapor passing through a tube ?48! wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line ?38!.

Abstract: A method is disclosed for maximizing the thermodynamic efficiency and the heat transfer capacity of a counter-current heat exchanger through the use of an optimized multi-component working fluid. Given the operational temperatures and pressures of the heat exchanger, the disclosure teaches a method for selecting the components for the working fluid and for determining the molar fractions of the components that determine the optimal mixture for the working fluid. Because the effective specific heat of a high pressure stream of this mixture is equal to the effective specific heat of a low pressure stream throughout the entire temperature range of the heat exchanger, the thermodynamic efficiency of the heat exchange process is maximized. In addition, because the difference between the enthalpies per unit mass of the two streams are maximized throughout the temperature range of the exchanger, this mixture provides optimal capacity for heat transfer in the heat exchanger.

Abstract: A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant coming from an air-cooled condenser is injected into a cyclone chamber [32] through the inlet tube [34]. While the liquid drains down a conical section [36] and out through a liquid line [38], the vapor phase moves up into a packing of metal platelets [42] which is cooled by a returning stream of cold vapor passing through a tube [48] wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line [38].

Abstract: A non-linear superconducting junction device comprising a layer of high transient temperature superconducting material which is superconducting at an operating temperature, a layer of metal in contact with the layer of high temperature superconducting material and which remains non-superconducting at the operating temperature, and a metal material which is superconducting at the operating temperature and which forms distributed Sharvin point contacts with the metal layer.

Abstract: A multilayer miniature low temperature rapid cooldown refrigerator in which a central cooling chamber for a device to be continuously cooled is connected to input and output refrigerant lines by micron sized channels formed in interfaces of glass or like plates, the channels including a counterflow heat exchanger and a capillary section and the channels being so arranged as to assure rapid cooldown immediately in the region of the device to be cooled.

Abstract: A novel apparatus is disclosed for use in controlling in a known and predictable manner the temperature of the top surface of a capillary die and the adjacent meniscus during the growth of a crystalline body. The novel apparatus comprises an adjustable heat shield assembly with relatively movable members which can be positioned in such a manner as to provide improved temperature control at the top end of the die which assists in ensuring that a crystalline body grown by means of the capillary die will have a substantially constant cross-sectional size.

Abstract: A microminiature cryogenic device for cooling in the milliwatt range includes a miniature refrigerator in which micron-sized fluid passages are defined in one or more internal surfaces of a laminate of glass or similar low thermal conductivity members by means of lithographic, etching or particle blasting techniques.

Abstract: A multilayer miniature low temperature refrigerator wherein a cooling chamber for a device to be continuously cooled is connected to an input and an output by micron sized channels or like passages in respective different interfaces of a laminate of glass or like plates.

Abstract: Noise generated by the tips of the fan blades in a turbofan jet propulsion engine is suppressed by generating an annular fluid layer or wake in the inlet of the turbofan engine forwardly from the fan blades and spaced inwardly from the inner wall of the inlet and by lining the inner wall of the inlet with an acoustically absorbent layer of material. Sound waves generated by the fan blades are reflected outwardly by the fluid layer and are absorbed in the acoustic absorbent layer on the inner wall of the inlet. In order for the wake to reflect sound waves, either the local fluid velocity in the wake must be lower than the fluid velocity of the surrounding airstream traveling through the inlet or the acoustic speed in the wake must be greater than or equal to the acoustic speed in the surrounding airstream. It is preferred that both conditions be met.

Abstract: Receptors are employed to which one or more fluroescent molecules are bound. When the receptors are bound to the epitopic sites on the surface and light of predetermined wave length is directed toward the surface, the fluorescing molecules are activated and fluoresce.In carrying out an assay, receptor is combined with an unknown suspected of containing molecules having the same epitopic sites bound to the surface. The receptor will bind to these molecules reducing the number of receptor sites available for binding to the epitopic sites on the surface. When the assay medium is contacted with the surface, the amount of receptor which binds to the surface, will be a function of available binding sites and, therefore, to the number of the molecules present in the unknown. Upon irradiation of the surface, substantially only the fluoroescent molecules bound to the surface will fluoresce. By monitoring the fluorescence, one can determine the presence and number of molecules of interest present in the unknown.