Patents Represented by Attorney Timothy S. Stevens
  • Patent number: 4999305
    Abstract: A method for titration flow injection analysis by introducing a multicomponent sample into a carrier stream which flows into a mixing/sensing cell and titrating with a reactant more than one component of the sample by sensing a plurality of endpoints. The apparatus of the invention includes a stirring means within the mixing/sensing cell which generates helical flow within the cell so that bubbles are not retained in the cell.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: March 12, 1991
    Inventors: Duane K. Wolcott, Ernest D. Graves, Jr., David G. Hunt
  • Patent number: 4999105
    Abstract: Apparatus and method for extracting a component from a sample across a membrane into an extractant and then injecting the extracted sample component into a chromatographic eluent and onto a chromatographic column to chromatographically analyze the extracted sample component. In essence, the advance provided by this invention is that the extractant and the eluent are the same and only one pump is used for pumping the eluent and extractant. In prior apparatus and methods in this field, the extractant and the eluent were separate and each had its own pump.
    Type: Grant
    Filed: August 5, 1988
    Date of Patent: March 12, 1991
    Assignee: The Dow Chemical Company
    Inventors: Richard G. Melcher, Hernan J. Cortes
  • Patent number: 4988155
    Abstract: An in-line fiber optic probe interface includes a sample cell with a bore therein defining an optical axis. A controller housing is centered by o-ring seals in the bore and a pathlength controller is mounted on the housing. A fiber optic probe is disposed in the housing and controller, sealed thereto by o-ring seals at multiple points to maintain the probe in appropriate alignment on the optical axis.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: January 29, 1991
    Assignee: The Dow Chemical Company
    Inventors: Richard S. Harner, Charles J. Myers
  • Patent number: 4968383
    Abstract: A method for adhesively bonding a first body to a second body, the first body comprising a metallic substrate, such as a piece of steel, or comprising a metallic substrate and a filler therein, such as ceramic fiber reinforced aluminum, the second body comprising any type of substrate, such as a piece of glass, plastic or metal. The first body is pretreated by placing it in the path of an energy beam, such as a laser beam, to form projections on the metallic substrate by evaporation and/or melting of the metallic substrate of the first body, substantially all of the projections being less than 20 micrometers in height, or to expose filler by evaporation of the metallic substrate of the first body. The second body can be untreated, pretreated as above or pretreated another way, such as by solvent washing or sandblasting. An adhesive is then coated on the pretreated area of the first body and the first body adhered to the second body.
    Type: Grant
    Filed: June 8, 1989
    Date of Patent: November 6, 1990
    Assignee: The Dow Chemical Company
    Inventors: Curtis L. Volkmann, John J. Kester, Gregory A. Stevens
  • Patent number: 4962042
    Abstract: In one embodiment the invention is a method for on-column valved injection gas chromatography by on-column injecting more than 5 microliters and less than one milliliter of sample consisting of a solvent and a component of interest into a retention gap/capiliary column system with an injection valve at a first carrier gas flow rate, followed by a substantially higher carrier gas flow rate to blow the solvent of the sample out of the system at a rapidly increased rate and then a return to a lower flow rate to chromatograph the component of interest. In another embodiment, less than 5 microliters of sample consisting of a solvent and a component of interest is on-column injected into a capillary column using an injection valve and a relatively high column inlet pressure of gas to move the sample from the injection valve into the colunm rapidly and with reduced carryover. Then, the pressure of carrier gas is reduced to a normal pressure for chromatography of the component of interest.
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: October 9, 1990
    Assignee: The Dow Chemical Company
    Inventors: Paul L. Morabito, Richard G. Melcher, Joseph F. Hiller, Terrence McCabe
  • Patent number: 4960444
    Abstract: A gas chromatography method for the determination of organic acids using an otherwise conventional gas chromatography system, the advance being injecting a predetermined volume of an aqueous sample containing the organic acids for separation in a gas chromatography column having a polycarbonate resin stationary phase. The use of the polycarbonate resin stationary phase results in a method more resistant to the development of tailing peaks and other problems than the use of prior stationary phases. The method is especially beneficial for determining acrylic acid monomer in mixtures of acrylamide monomer and water.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: October 2, 1990
    Assignee: The Dow Chemical Company
    Inventor: Labib Ghaoui
  • Patent number: 4946652
    Abstract: Apparatus for selectively and precisely placing a chemical analysis probe (such as a fiber optic probe): (1) in a liquid sample contained in an open-mouthed sample vessel positioned on a sample support, or (2) in a wash collection chamber. Any residual sample remaining on the probe can be washed from it with a stream of volatile wash liquid when the probe is in the wash collection chamber and jets of gas can be directed onto the washed probe to speed the evaporation of any residual wash liquid from the probe. A latch can be used to hold the probe in the wash collection chamber.
    Type: Grant
    Filed: December 30, 1987
    Date of Patent: August 7, 1990
    Assignee: The Dow Chemical Company
    Inventors: Lamar R. Dewald, William E. Ryan
  • Patent number: 4931125
    Abstract: A method for adhesively bonding a first body to a second body, the first body comprising a non-metallic substrate, such as a piece of rubber, or comprising a non-metallic substrate and a filler therein, such as a piece of fiberglass reinforced plastic, the second body comprising any type of substrate, such as a piece of glass, plastic or metal. The first body is pretreated by placing it in the path of an energy beam, such as a laser beam, to form projections on the non-metallic substrate by evaporation of the non-metallic substrate of the first body, or to expose filler by evaporation of the non-metallic substrate of the first body. The second body can be untreated, pretreated as above or pretreated another way, such as by solvent washing or sandblasting. An adhesive is then coated on the pretreated area of the first body and the first body adhered to the second body. The cured adhesive interlocks with the projections and/or the exposed filler to produce a stronger bond.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: June 5, 1990
    Assignee: The Dow Chemical Company
    Inventors: Curtis L. Volkmann, John J. Kester, Gregory A. Stevens
  • Patent number: 4927539
    Abstract: An anion-exchange chromatographic packing composition which comprises:a substrate which consists essentially of particles having cation-exchanging sites at least on their available surfaces, the particles being of a diameter of between about 1 to about 75 microns; anda liquid coating which consists essentially of a hydrophilic, water soluble, film forming resin having anion-exchanging sites which attract available cation-exchanging sites of the substrate, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the substrate particles. The invention further includes a chromatographic column and process using the described packing composition.
    Type: Grant
    Filed: October 24, 1988
    Date of Patent: May 22, 1990
    Assignee: The Dow Chemical Company
    Inventors: Timothy S. Stevens, Martin A. Langhorst, Osro W. Randall, III
  • Patent number: 4920056
    Abstract: Apparatus and method for automatic microbatch reaction including a reactor having a reaction chamber, such as a 1.5 milliliter plastic centrifuge tube having a conical bottom. An automatically actuated injection valve is used to inject less than 1 milliliter of a sample into the reaction chamber. One or more automatically actuated reagent valves are used to introduce respective pressurized reagents into the reaction chamber to process the sample. The volume of the reagent(s) introduced into the reaction chamber is less than 1 milliliter and controlled by the on time of the respective reagent valve. The automatically actuated valves are controlled by a computer based timer. A sensor positioned in the chamber, such as a pH electrode, can be used to analyze the processed sample in place or the processed sample can be analyzed by flowing it from the reaction chamber through a flow-through detector, such as a flow-through spectrophotometer.
    Type: Grant
    Filed: February 19, 1988
    Date of Patent: April 24, 1990
    Assignee: The Dow Chemical Company
    Inventor: Purnendu K. Dasgupta
  • Patent number: 4913821
    Abstract: A chromatographic method for the determination of individual phenols in water by adding a halogenating agent to the water, e.g., using the bromate-bromide reaction to generate tribromide ions which react with the phenols to form bromo-derivatives of the phenols, then to permeate the bromo-derivatives across a membrane, e.g., a silicone rubber membrane, into a liquid extractant, e.g., a dilute aqueous solution of sodium hydroxide and acetonitrile, and then determining the permeated bromo-derivatives in the liquid extractant by chromatography, e.g., by injecting the liquid extractant containing the permeated bromo-derivatives into a reverse phase liquid chromatographic system.
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: April 3, 1990
    Assignee: The Dow Chemical Company
    Inventors: Richard G. Melcher, Earl E. Burt, III
  • Patent number: 4909588
    Abstract: A fiber optic probe adapted to be immersed in a fluid medium has an opening at one end in which is accommodated an optical window through which light may be transmitted from and to the optical fibers. Seals between the optical element and the probe body are provided to prevent the leakage of fluid past the window into the probe body. One or more resilient biasing springs constantly apply a yieldable, compressive force on the seals regardless of thermal expansion and contraction of any part of the probe.
    Type: Grant
    Filed: August 25, 1988
    Date of Patent: March 20, 1990
    Assignee: The Dow Chemical Company
    Inventors: Richard S. Harner, Bruce W. Gutzmann
  • Patent number: 4905504
    Abstract: A foam pulse rheometer measures the total integrated stress response of a foaming polymer to a short duration strain pulse applied to the polymer, from which can be calculated the equilibrium modulus and the zero shear viscosity of the foaming polymer during the foaming reaction. A shear plate mounted to a load cell above a jacket extends downwardly into a foaming polymer within the jacket. Under the application of a vertical square wave strain pulse to the jacket, the load cell senses the shear force exerted upon the shear plate by the foaming polymer. Simultaneously, a video camera and recorder monitors the surface area of the plate acted upon by the jacket. For each pulse, simultaneously occurring discrete sensed force values and discrete monitored surface area values can be used to compute the total integrated stress response, from which can be calculated the equilibrium modulus and the zero shear viscosity.
    Type: Grant
    Filed: March 15, 1989
    Date of Patent: March 6, 1990
    Assignee: The Dow Chemical Company
    Inventors: Craig J. Carriere, David H. Bank, Christopher P. Christenson
  • Patent number: 4889380
    Abstract: A clamp-on automotive sun-filter assembly having an injection molded opaque indicia-bearing clamping panel and integrally formed spring clamps for attachment to a conventional automotive sun visor, and a tinted sun filter panel hinged to and swung below an edge of the clamping panel, is improved by filling in the die clearance apertures of the clamping panel with inserts to provide an uninterrupted printing surface.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: December 26, 1989
    Inventor: Albert Pillifant, Jr.
  • Patent number: 4886965
    Abstract: A method for determining the wavelength accuracy of a variable wavelength liquid chromatography detector in the low UV range comprising filling the cell of the detector with a test solution and varying the indicated wavelength of detection to find the indicated wavelength of maximum absorbance in a wavelength region around a reference wavelength of the test solution and then calculating the difference between the indicated wavelength of maximum absorbance and the reference wavelength to determine the accuracy of the indicated wavelength of the detector. The test solution contains terbium III ions in a solvent such as n-propanol so that the absorbance maximum of the test solution does not shift more than about 0.5 nm for a spectral bandpass ranging from 2 to 6 nm.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: December 12, 1989
    Assignee: The Dow Chemical Company
    Inventor: J. Benjamin Esquivel H.
  • Patent number: 4872334
    Abstract: A method for temperature programmed capillary column gas chromatography characterized in that carrier gas is flowed in an amount greater than that under normal separation conditions for a term starting from before injection of a sample or immediately after the injection and ending at any time point from immediately after a solvent in the sample commences to enter into a column to the solvent finishing passing through the column. The invention is also apparatus for the above method characterized in that the apparatus has two flow paths for carrier gas which, for example, join to one flow path before a sample injection device, and one of the flow paths has a valve which can rapidly stop or decrease the flow of the carrier gas in that flow path.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: October 10, 1989
    Assignee: The Dow Chemical Company
    Inventor: Chuichi Watanabe
  • Patent number: 4861407
    Abstract: A method for adhesively bonding a first body to a second body, the first body comprising a metallic substrate, such as a piece of steel, or comprising a metallic substrate and a filler therein, such as ceramic fiber reinforced aluminum, the second body comprising any type of substrate, such as a piece of glass, plastic or metal. The first body is pretreated by placing it in the path of an energy beam, such as a laser beam, to form projections on the metallic substrate by evaportion and/or melting of the metallic substrate of the first body, substantially all of the projections being less than 20 micrometers in height, or to expose filler by evaporation of the metallic substrate of the first body. The second body can be untreated, pretreated as above or pretreated another way, such as by solvent washing or sandblasting. An adhesive is then coated on the pretreated area of the first body and the first body adhered to the second body.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: August 29, 1989
    Assignee: The Dow Chemical Company
    Inventors: Curtis L. Volkmann, John J. Kester, Gregory A. Stevens
  • Patent number: 4854700
    Abstract: A column holder for on-column photometric detection capillary liquid chromatography incorporating a body and a pair of straight edges attached to the body. The straight edges can be conveniently made from a razor blade. The body has two passageways through it that are transverse and intersecting. The first passageway is dimensioned so that a capillary column can be slipped into it or removed from it by hand. The other passageway is for the passage of a light beam from a liquid chromatography photometric detector. The straight edges are slightly separated to form an optical slit in front of the capillary column and are securely clamped to the body of the column holder. A capillary column can be removed from the column holder and be replaced with another capillary column without damaging it and without the necessity of repositioning the slit.
    Type: Grant
    Filed: June 15, 1988
    Date of Patent: August 8, 1989
    Assignee: The Dow Chemical Company
    Inventors: Sergio S. Cutie, Martin A. Langhorst, Stewart P. Wood
  • Patent number: 4850636
    Abstract: A method of assembling a door and a door assembly comprising an outer door shell and inner door supporting member therefor. The supporting member is hinged at one end to a door frame. The other end of the supporting member is slidably accommodated in and occupies the outer door shell through an aperture in a lateral edge of the door shell. The supporting member can carry a window glass holder, such as a channel strip screwed to the supporting member, and this combination is called a cartridge assembly.
    Type: Grant
    Filed: September 17, 1987
    Date of Patent: July 25, 1989
    Assignee: The Dow Chemical Company
    Inventors: John W. McLaren, Jeffery D. Zawisza, Walter E. F. Rupprecht
  • Patent number: 4845809
    Abstract: A position retentive hinge assembly is provided in which two bodies are swing about one or more axially aligned hinge pins. The first body has at least two paired supports holding the one or more hinge pins. The second body has a receiving and retaining portion for each hinge pin. The inner end face of at least one support is non-planar and cooperates with a non-planar opposed adjacent end face of a receiving and retaining portion of the second body. A spring confined between a support and an end face urges the non-planar opposed faces together and position retentive cam and cam follower action is had as the bodies are swung pivotally.
    Type: Grant
    Filed: March 21, 1988
    Date of Patent: July 11, 1989
    Inventor: Albert Pillifant, Jr.