Measurement Includes Change In Volume Or Pressure Patents (Class 436/148)
  • Patent number: 5700695
    Abstract: A sample collection and manipulation apparatus (2), typically used for collecting and manipulating a blood sample and measuring a component of that sample with the use of a reagent or ion-selective electrodes, includes a body member (4, 6, 8) defining a thermal pressure chamber (22) and a sample port (10). A measurement chamber (26) is formed along a fluid passageway (42, 16, 24) connecting the thermal pressure chamber with the sample port. The air within the thermal pressure chamber is preheated (54, 56, 60, 62, 63/65) to reduce its density and the sample port is then placed in contact with the liquid. As the gas cools, a partial vacuum is created within the thermal pressure chamber to draw a liquid sample through the passageway and into the measurement chamber. Appropriate analyte measurement techniques, such as optical or electrochemical, can then be carried out. Applications include the testing of blood gases, glucose, hemoglobin, electrolytes, coagulation and therapeutic drugs.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: December 23, 1997
    Assignee: Zia Yassinzadeh
    Inventors: Zia Yassinzadeh, Paul J. Lingane
  • Patent number: 5665311
    Abstract: An apparatus for measuring physical properties of blood is disclosed. Two reservoirs are provided connected to a receptacle means by at least two elongated tubes. A punching station located along the two tubes permits the simultaneous punching of holes to simulate bleeding in the tubes. The bleeding of the tubes is monitored to indicate the haemostasis properties of blood flowing through the elongated tubes. Monitoring is effected by measuring the downstream pressure of a punched tube. Alternate embodiments include the addition of third channel having a collagen material within the channel. Platelet aggregation on the collagen material is observed as a measure of haemostasis properties of the blood.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: September 9, 1997
    Inventors: Peter Gorog, Iren Kovacs
  • Patent number: 5650330
    Abstract: Lipid bilayers which incorporate poly-3-hydroxybutyrate/polyphosphate ion channels. The ion channels are preferably purified polyhydroxybutyrate polyphosphate complexes extracted from organisms or prepared from the individual constituents which have been size selected. The bilayers are useful for testing the affect of various molecules and ions on the channel which correlates to the in vivo result. The bilayers are useful for transporting the channels into cells or other bilayers.
    Type: Grant
    Filed: March 13, 1996
    Date of Patent: July 22, 1997
    Assignee: Board of Trustees operating Michigan State University
    Inventor: Rosetta N. Reusch
  • Patent number: 5639667
    Abstract: In a pipe containing a fluid wherein particles circulate, at least one detector is attached. The detector includes a cavity in fluid communication with the pipe by a vent whose section, at least at an opening for fluid communication with a pipe is of the same dimensions as that of the circulating particles. A periodic exciter such as a source of acoustical waves or a generator of the periodic motion piston type suitable for inducing alternate pressure variations in the fluid in the cavity is coupled with the cavity. The excitation frequency can be selected in keeping with a resonance frequency of the cavity. Signals representative of the pressure variations of the excited fluid, resulting from flowing of the particles past the opening of each vent are measured. Processing of the signals allows the velocity of the particles to be determined. Other parameters of the particles can be determined by means of two distinct detectors coupled with the pipe.
    Type: Grant
    Filed: June 21, 1995
    Date of Patent: June 17, 1997
    Assignee: Institut Francais du Petrole
    Inventors: Fran.cedilla.ois Heslot, Claude Beauducel
  • Patent number: 5622869
    Abstract: An apparatus for detecting obstructions of a flow line. A detector housing is provided having a cavity therein. The detector housing has first and second openings into the cavity. The flow line is attached to the detector housing establishing a flow path through the first opening, the cavity, and the second opening, respectively. A pressure detector detects changes in pressure within the cavity, indicating the presence of an obstruction.
    Type: Grant
    Filed: July 10, 1995
    Date of Patent: April 22, 1997
    Assignee: Akzo Nobel N.V.
    Inventors: Gregory D. Lewis, Dean L. Keiter, Mario Moreno
  • Patent number: 5580793
    Abstract: Process and device for determining para content X.sub.1 of a hydrogen gas stream, in which temperature T.sub.1 as well as pressure p.sub.1 of the hydrogen gas stream are measured before its entry into at least adiabatically-operated para-ortho-conversion catalyst. The hydrogen gas stream flows through the para-ortho-conversion catalyst until equilibrium is established. Thereafter, temperature T.sub.2 as well as pressure p.sub.2 of the hydrogen gas stream are measured after the hydrogen gas exits from the para-ortho-conversion catalyst or are measured after the last of the latter exits the catalyst. Para content X.sub.1 of the hydrogen gas stream, at the instant before entering the para-ortho-conversion catalyst, is determined by relations h.sub.1 (X.sub.1, T.sub.1, p.sub.1)=h.sub.2 (X.sub.2, T.sub.2, p.sub.2) and X.sub.2 =X.sub.g (T.sub.2) in equilibrium, in which h.sub.1 is the enthalpy of the hydrogen gas stream at the inlet of the para-ortho-conversion catalyst and h.sub.
    Type: Grant
    Filed: February 2, 1995
    Date of Patent: December 3, 1996
    Assignee: Linde Aktiengesellschaft
    Inventor: Manfred Wanner
  • Patent number: 5516489
    Abstract: An apparatus for testing peroxide concentration in a gaseous sterilant. A preferred embodiment of the apparatus includes a condenser for condensing the gaseous sterilant into a liquid condensate; an aliquot collector of predetermined volume to receive the condensate; a reaction chamber containing a catalyst for dissociating the peroxide; and a pressure monitor for detecting pressure changes in the reaction chamber as a function of time. The pressure monitor of this apparatus is capable of detecting a threshold pressure and an upper pressure and it includes a timer to measure time change between detection of the threshold pressure and the upper pressure.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: May 14, 1996
    Assignee: Despatch Industries, Inc.
    Inventors: Hans L. Melgaard, Louis A. Larson
  • Patent number: 5451373
    Abstract: An apparatus for detecting obstructions of a flow line. A detector housing is provided having a cavity therein. The detector housing has first and second openings into the cavity. The flow line is attached to the detector housing establishing a flow path through the first opening, the cavity, and the second opening, respectively. A pressure detector detects changes in pressure within the cavity, indicating the presence of an obstruction.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: September 19, 1995
    Assignee: AKZO N.V.
    Inventors: Gregory D. Lewis, Dean L. Keiter, Mario Moreno
  • Patent number: 5369033
    Abstract: A system for monitoring changes in the amount of contaminants present in a flowing stream of supercritical fluid. A sample stream is removed from a flowing stream of supercritical fluid and subjected to reduced pressure. The supercritical fluid turns into gas at the reduced pressure with the contaminants remaining in a non-gaseous form. A quartz crystal microbalance system measures changes in the amount of non-gaseous contaminants present in the sample stream. The system is useful in monitoring both cleaning processes and extraction processes utilizing supercritical fluids.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: November 29, 1994
    Assignee: Hughes Aircraft Company
    Inventors: Edward S. Di Milia, Darrell A. Gleichauf, Thomas E. Whiting
  • Patent number: 5366901
    Abstract: An apparatus for the analysis of carbon products enables air reactivity, CO.sub.2 reactivity, soot index and coefficient of thermal expansion of the carbon products to be determined in one analysis operation. The apparatus includes vertical and/or horizontal tube furnaces, each of which is provided with devices for weighing, temperature registration and/or registration dilation. Introduction of gas takes place via one end of each of the tube furnaces. Each of the furnaces is connected to a joint processing unit which checks the various instruments and registers the various instruments and registers and processes the analytical data.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: November 22, 1994
    Assignee: Norsk Hydro a.s.
    Inventors: Knut Bergli, Trygve Foosnaes, Tormod Naterstad
  • Patent number: 5350549
    Abstract: Cementitious compositions useful as lightweight aggregates are formed from a blend of spent bed material from fluidized bed combustion and fly ash. The proportions of the blend are chosen so that ensuing reactions eliminate undesirable constituents. The blend is then mixed with water and formed into a shaped article. The shaped article is preferably either a pellet or a "brick" shape that is later crushed. The shaped articles are cured at ambient temperature while saturated with water. It has been found that if used sufficiently, the resulting aggregate will exhibit minimal dimensional change over time. The aggregate can be certified by also forming standardized test shapes, e.g., cylinders while forming the shaped articles and measuring the properties of the test shapes using standardized techniques including X-ray diffraction.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: September 27, 1994
    Assignee: Valley Forge Laboratories, Inc.
    Inventor: Michael J. Boyle
  • Patent number: 5342580
    Abstract: An apparatus and method for measuring an amount of gas adsorbed on or desorbed from a solid and for analyzing and surveying reactions of a gas with a solid. Governing parameters include pressure, temperature and gas flow rate. The apparatus and method provide accurate measurement utilizing temperature programmed characterization and the volumetric method. The method is useful at both very high and very low pressures.
    Type: Grant
    Filed: April 17, 1990
    Date of Patent: August 30, 1994
    Inventor: Alan Brenner
  • Patent number: 5310658
    Abstract: A pressure/vacuum method and instrument for detecting biological activities in blood culture vials, that is non-invasive, does not require chemical sensors, does not require high-brightness short-wavelength light sources, is safe against eventual extreme high pressure values, and is head-space-temperature compensated. A culture medium and blood specimen are introduced into a sealable glass vial. The normally incompressible fluid suspension is made compressible through the use of a partially inflated gas bag submerged within the medium. The changes in fluid position that result from bacterial growth related pressure changes within the vial head space are measured to detect biological activities.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: May 10, 1994
    Assignee: Becton, Dickinson and Company
    Inventor: Klaus W. Berndt
  • Patent number: 5270218
    Abstract: An analytical method which comprises sampling a predetermined amount of a liquid sample, bringing the sample to a vapor-liquid equilibrium at a predetermined temperature and pressure, separating the resultant gaseous and liquid fractions from each other, and analyzing the gaseous fraction as a gas sample and the liquid fraction as a liquid sample, and an apparatus for practicing the analytical method. By this method or apparatus, the light and heavy fractions of a substance can be simultaneously analyzed in composition and chemical structure. This enables the modification and the service life of a chemical substance like a lubricating oil, in which the qualities may change with the passage of time, to be estimated or foreseen.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: December 14, 1993
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventor: Makoto Ikeda
  • Patent number: 5266492
    Abstract: A method of determining the critical vapor pressure of a hygroscopic material, such as a drug. A drug sample is placed in a substantially isothermal environment. A vapor, such as water vapor, at a given pressure is then placed in the ambient air over the drug. The rate of heat production from this sample at the given water vapor pressure, or the humidity of the air above the sample, is then measured. The water vapor pressure over the drug is gradually increased. Simultaneously, the rate of increase in heat production from the drug sample, or the rate of change of the relative humidity of the air above the drug sample, is measured. A marked increase in the rate of heat production generated by the drug, or a marked change in the relative humidity of the air over the sample, signals the attainment of the critical water vapor pressure.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: November 30, 1993
    Assignee: Baxter International Inc.
    Inventors: Ray W. Wood, Lee D. Hansen, John W. Crawford
  • Patent number: 5260192
    Abstract: A method and apparatus for automatically and rapidly, retrieving counting and/or analyzing at least one selected population of cells or formed bodies, such as a white blood cell population and at least one subset thereof of a whole blood sample or portion thereof. A volume of a biological medium containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. A multipart blood cell analysis is obtained with a single sensing parameter by depleting at least one WBC subset population. The percentage of a desired WBC population subset or the overlapping of WBC subset populations also can be obtained by subtracting one or more obscuring WBC subset populations.
    Type: Grant
    Filed: August 12, 1992
    Date of Patent: November 9, 1993
    Assignee: Coulter Corporation
    Inventors: Thomas Russell, Constance M. Hajek, Carlos M. Rodriguez, Wallace H. Coulter
  • Patent number: 5231005
    Abstract: A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected population of cells or formed bodies, such as a white blood cell population and at least one subset thereof of a whole blood sample or portion thereof. A volume of a biological medium containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The opacity and/or volume parameter of the cells can be modified and the mixture is then counted and analyzed in one or more steps to obtain the desired white blood cell population and subset analysis. The biological sample can be a whole blood sample and the reactant can include or be a lyse or a monoclonal antibody bound to microspheres, which will bind to specific ones of the cells or a combination of lyse and microspheres with antibody bound thereto.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: July 27, 1993
    Assignee: Coulter Corporation
    Inventors: Thomas Russell, Kenneth H. Kortright, Wallace H. Coulter, Carlos M. Rodriguez, Ronald Paul, Constance M. Hajek, James C. Hudson
  • Patent number: 5141873
    Abstract: This invention relates to a process for the selective determination of the oncentration of a substance dissolved in a solvent by means of an osmosis cell. The osmosis cell according to the invention contains a substance not contained in the solution to be tested, which is either practically insoluble or is impermeable for the membrane. This substance reacts chemically with the substance permeating into the osmosis cell, with a product resulting from it in the cell or with a product resulting from the substance in the solution to be tested and permeating into the cell. Reaction products are thereby formed which produce a pressure in the osmosis cell, which is different from the osmotic pressure of the chemically converted portion of the substance. A pressure increase thereby occurs in the cell, from which the concentration of the substance in the solution to be tested can be determined on the basis of standard values.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: August 25, 1992
    Assignee: Kemforschungsanlage Julich Gesellschaft mit beschrankter Haftung
    Inventors: Ernst Steudle, Gerd Boling, Josef Zillikens
  • Patent number: 5120648
    Abstract: A chemical analyzer in which the measurement of the change in attenuation of RF radiation propagated through a sample is used as the basis for calculating the change in concentration of a given chemical in the sample. Also disclosed are various probe and system designs which facilitate the use of RF attenuation as a basis for measurement of certain chemical characteristics of a sample.
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: June 9, 1992
    Assignee: Lim Technology Laboratories, Inc.
    Inventors: Franklin Lim, William H. Bingham, Richard D. Moss, Lloyd T. Hall, III
  • Patent number: 5081045
    Abstract: An apparatus and method are disclosed for the measurement of hydrogen peroxide concentration from within a textile bleaching bath. The apparatus comprising a sample chamber, a process valve between a source of the solution to be tested and the sample chamber, a reagent valve between a source of reagent and the sample chamber, a pressure measurement tube attached to and extending from the sample chamber, an exhaust valve in communication with the sample chamber, and a pump at a location between the exhaust valve and exhaust device. The process measures hydrogen peroxide concentration by the pressure of the oxygen given off into a known volume as a result of a chemical reaction between the hydrogen peroxide and sodium hypochlorite.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: January 14, 1992
    Inventor: Errol McGill
  • Patent number: 5001067
    Abstract: Correcting an initial measurement of the concentration of a first water soluble species dissolved in a water-based component of a biological fluid that also includes a second water soluble species and a volume occupying component, the initial measurement having been taken using an original sample of the fluid that had been diluted by an amount of additional aqueous solution to form a diluted sample is disclosed; the concentration of the second water soluble species is measured in an undiluted sample of the biological fluid to obtain a direct concentration and is measured using a diluted sample of the fluid to obtain an indirect concentration, and the initial measurement of concentration of the first species is adjusted based on a combination of the direct and indirect concentration determinations of the second species.
    Type: Grant
    Filed: September 18, 1989
    Date of Patent: March 19, 1991
    Assignee: Nova Biomedical Corporation
    Inventors: Robert L. Coleman, Chung C. Young
  • Patent number: 4988626
    Abstract: An analysis process is provided for the determination of a complete material balance of a chemical reaction, especially useful in the studies of catalyst activity. A complete material balance is obtained by determining the output flow from a reactor at the temperature and pressure conditions of the chemical reaction. The reactor output flow is determined by first analyzing the effluent volume composition at the temperature and pressure conditions of the reaction. Subsequently, the effluent is expanded and the volume composition and flow rate of the expanded effluent are measured. From these measurements and the volume composition at the reactor output, the output flow from the reactor is determined. A strict material balance is then possible by comparing the input flow rate and volume composition to the output volume composition and flow rate, thereby establishing a complete material balance at the reaction temperature and pressure.
    Type: Grant
    Filed: June 17, 1986
    Date of Patent: January 29, 1991
    Assignee: Institut Francais Du Petrole
    Inventors: Hubert Ajot, Edouard Freund, Pierre Grandvallet
  • Patent number: 4971764
    Abstract: The venting mechanism for discharging steam from a sterilizing chamber has a variable effective orifice area controllable in response to decreasing pressure. The throughput of the venting mechanism increases as the pressure decreases, thereby compressing the venting stage of a sterilization cycle without increasing the loss of liquid inherently experienced in sterilizing liquid loads.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: November 20, 1990
    Assignee: MDT Corporation
    Inventor: Donald W. Albright
  • Patent number: 4902628
    Abstract: An apparatus and method to deter circumvention of sobriety breath tests. As a precondition to passing the test, the invention requires an operator/test subject to apply a suction at the sample delivery port within a predetermined time of delivering a breath sample thereinto. The delay, if any, between the required sucking and the delivery of the breath sample is selected to be short thereby deterring a substitution of gas sources. In this way, the invention effectively deters circumvention of sobriety breath tests due to attempts to supply bogus gas samples from a positive pressure gas source incapable of applying a reverse pressure gradient.
    Type: Grant
    Filed: August 24, 1988
    Date of Patent: February 20, 1990
    Assignee: Guardian Technologies, Inc.
    Inventor: R. Gregory Blair
  • Patent number: 4886653
    Abstract: A process and apparatus for producing an aqueous solution of chlorine dioxide and chlorine wherein the likelihood of autodecomposition of chlorine dioxide is significantly reduced or practically eliminated and, in the unlikely event that such CLO.sub.2 autodecomposition occurs, it is quickly detected and the process is automatically corrected.
    Type: Grant
    Filed: March 25, 1988
    Date of Patent: December 12, 1989
    Assignee: Olin corporation
    Inventors: Kenneth E. Gasper, Philip A. Vella
  • Patent number: 4765963
    Abstract: A sampled flow of water is extracted from a water conduit 1 carrying impure water by a sampling tube 2, the pressure at a point in the sampling tube is kept constant by a constant pressure maintaining valve 4, and the sampled water passed through a filter 7. The flow rate of sampled water passing through the filter 7 is measured by a flow meter 8. A value corresponding to the total amount or level of impurity in the sampled water is evaluated by an operation circuit 9 at a prescribed time interval, based on the time-dependent change in the result of measurement of the flow meter 8 and the total amount or level of impurities in pure water is thus measured indirectly.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: August 23, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasukazu Mukogawa, Katsuhiko Tamura, Takaaki Fukumoto
  • Patent number: 4758408
    Abstract: An automatic oxygen absorption measuring system has a controllable source of pressurized oxygen, a controllable venting device, and a device for indicating incremental gas volume changes connected through a controlled gas reservoir to an oxygen circulating testing section where oxygen is passed through a liquid sample at a fixed temperature. Upon the liberation of other gases than oxygen or absorption of oxygen, the gas pressure changes a liquid fluid level in the device for indicating incremental gas changes. An electronic circuit causes the venting or inputting of gas until an equilibrium pressure is obtained. Each change is noted on a recording device. The device for indicating incremental gas volume changes has two glass bulbs attached in line with a manometer filled with electrically conductive liquid fluid. Four electrical contacts placed about the bulbs indicate the level of the liquid fluid.
    Type: Grant
    Filed: February 27, 1985
    Date of Patent: July 19, 1988
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Arthur A. Krawetz, Theodore Tovrog
  • Patent number: 4677244
    Abstract: An apparatus and method for manipulating the temperature and pressure of the hydrocarbon phase in an acid settler vessel associated with a catalytic alkylation process and apparatus, wherein the hydrocarbon phase in the acid settler vessel is regulated by controlling the amount of rerun catalyst stream entering the hydrocarbon phase of the acid settler vessel. In response to a detected temperature or pressure of the hydrocarbon phase above a set point, the flow of rerun catalyst stream to the hydrocarbon phase of the acid settler vessel is decreased. This decrease in flow to the hydrocarbon phase may be accompanied by an increase in flow of rerun catalyst vapor to the catalyst phase of the acid settler vessel.
    Type: Grant
    Filed: November 29, 1985
    Date of Patent: June 30, 1987
    Assignee: Phillips Petroleum Company
    Inventors: Henry K. Hachmuth, Keith W. Hovis
  • Patent number: 4637735
    Abstract: A bench-scale apparatus for measuring the heat-release rate of pyrolysis vapors of a material sample includes an oven having a heated chamber for receiving the sample, a flue and at least one entry port, a radiometer having a radiation sensor disposed in relation to the flue of the oven such that an area into which burning pyrolysis vapors are directed from the flue is adjacent to the radiation sensor, a fuel-gas control valve in communication with the entry port of the oven, and an electronic flow meter for measuring the amount of fuel-gas passing through the control valve, wherein signals from the radiometer operate the fuel-gas control valve to provide an amount of fuel-gas sufficient to maintain a flame of the vapors at a predetermined height, and wherein the meter measures the amount of fuel-gas such that the measurement of the meter is used to indicate the heat-release rate of the pyrolysis vapors.
    Type: Grant
    Filed: January 27, 1986
    Date of Patent: January 20, 1987
    Assignee: Factory-Mutual Research Corporation
    Inventors: John de Ris, George H. Markstein
  • Patent number: 4483824
    Abstract: Long-term monitoring of pollutants or moisture in a fluid stream, such as an air stream, is achieved by electrically measuring (and optionally recording) pressure changes caused by a reaction between a pollutant or moisture in the stream and a chemical capable of reacting with such pollutant or moisture. The invention is useful for monitoring apparatus used in environment protection as well as measuring apparatus in determining moisture concentrations in, for example, protective or carrier gas streams utilized in semiconductor technology.
    Type: Grant
    Filed: October 13, 1982
    Date of Patent: November 20, 1984
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hans Pink
  • Patent number: 4452898
    Abstract: The volume change of a hydraulic cement slurry can be measured by measuring the amount of pressurized gas which flows into or out of the volume initially occupied by the slurry during the setting of the cement, for example, where the slurry is one formed by dissolving in the slurry mix water a correlated amount of gas-forming reactants having a delayed rate of reaction such that the gas production occurs mainly at the time the volume of the slurry mix water is being reduced to a low value during the setting and hardening of the cement.
    Type: Grant
    Filed: November 10, 1981
    Date of Patent: June 5, 1984
    Assignee: Shell Oil Company
    Inventor: Edwin A. Richardson
  • Patent number: 4448751
    Abstract: A testing apparatus is provided for measuring changes in the bulk volume and gas permeability of a cement slurry, such as one formed by dissolving in the slurry mix water a correlated amount of gas-forming reactants having a delayed rate of reaction such that the gas production occurs mainly at the time the volume of the slurry mix water is being reduced to a low value during the setting and hardening of the cement.
    Type: Grant
    Filed: November 10, 1981
    Date of Patent: May 15, 1984
    Assignee: Shell Oil Company
    Inventor: Edwin A. Richardson
  • Patent number: 4368072
    Abstract: A method of controlling the vapor pressure inside of an iodide decomposition vessel or apparatus for an iodide decomposition process by directly measuring the pressure inside the cell and adjusting the temperature of the lid of the cell. Zirconium and hafnium may be purified by the method.
    Type: Grant
    Filed: May 27, 1981
    Date of Patent: January 11, 1983
    Assignee: Teledyne Industries, Inc.
    Inventor: Mark B. Siddall