Abstract: A novel process for preparing superconductor of bismuth-containing compound oxide such as Bi--Sr--Ca--Cu system.In the present invention, firstly an intermediate compound oxide containing metal elements of the superconductor except bismuth is prepared and then the intermediate compound oxide is contacted with bismuth oxide vapour at a temperature between 750.degree. and 950.degree. C. so that bismuth oxide is reacted with said intermediate compound oxide.
Abstract: A two-part test cartridge for use in a centrifugal analyzer for measuring the concentration of different electrolytes in blood or blood serum samples has one part which is disposable and which is characterized by a sample entry port, one or more filled calibrant chambers, a waste chamber and passages between various chambers; and a second, mating part which is reusable and which is characterized by an ISE, a power supply and circuitry therefor, and a series of chambers and passages adapted for communication with the series of chambers and passages in the disposable part.
Type:
Grant
Filed:
April 12, 1989
Date of Patent:
July 10, 1990
Assignee:
Abbott Laboratories
Inventors:
Vidas P. Kazlauskas, Roger A. Janczak, Benton A. Durley, III
Abstract: A process for the preparation of Langmuir-Blodgett layer systems is described. The process comprises transferring a monolayer to a solid substrate having an electrically conductive surface by applying an electric potential, thereby oxidizing or reducing an electroactive molecule present in the monolayer. The layer systems so obtained can be used, for example, as electrically conductive layers or as sensors.
Abstract: A variation of Pulsed Coulometric Detection (PCD) is described in which the detection potential is scanned in a cyclic fashion during current integration to achieve automatic and virtual elimination of baseline drift caused by surface roughening and changes in pH. The technique is examined at a Au electrode for flow-injection determination if thiourea which is typical of numerous sulfur compounds whose anodic reactions are catalyzed by formation of surface oxide. The baseline decays quickly to a near-zero equilibrium value following start-up and is unchanged for a pH step of ca. 2 units. The technique is concluded to be compatible with pH-gradient chromatography.
Type:
Grant
Filed:
September 26, 1988
Date of Patent:
July 10, 1990
Assignee:
Iowa State University Research Foundation, Inc.
Abstract: An oxygen sensor element including an oxygen ion conductive solid electrolyte body, and electrode layers formed on opposite surfaces of the oxygen ion conductive solid electrolyte body. The electrode layers are mainly constituted by a platinum group metal in which a refractory material is dispersed.
Abstract: A limiting current-type oxygen sensor including (a) an oxygen ion-permeable substrate made of a zirconia solid electrolyte having a gas diffusion pore extending between first and second surfaces of the substrate for rate determination by oxygen diffusion through the pore; (b) a first porous electrode formed on the first surface of the substrate in an area including an opening of the gas diffusion pore; (c) a second porous electrode formed on the second surface of the substrate such that it is opposite to the first porous electrode via the substrate; (d) a sealing member fixed to the second surface of the substrate for sealing the second porous electrode such that the internal chamber is defined on the second porous electrode; and (e) a heating means mounted to the sealing member.
Abstract: Disclosed is a method of semiconductor device fabrication involving the detection of water in a dielectric layer that is part of the body of such device. At relatively high values of a voltage applied across the dielectric layer, water that is present in the dielectric decomposes and releases protons. Varying the applied voltage gives rise to a displacement current. The released protons contribute an ionic component to the displacement current. The ionic component is detected.
Type:
Grant
Filed:
August 18, 1989
Date of Patent:
July 3, 1990
Assignee:
American Telephone and Telegraph Company
Inventors:
John M. Andrews, Jr., Nadia Lifshitz, Gerald Smolinsky
Abstract: An analytical method using a sensor of the enzyme electrode type is provided for determining in a sample the concentration of an analyte reactive with an enzyme present on the sensor to produce an electrochemically active species detectable by the sensor, which comprises applying a potential across the sensor to cause an electrical current to flow therethrough, contacting the sensor with the sample thereby causing a change in the current flow and, when a working potential is applied across the sensor, determining the concentration of the analyte as a function of the change in the current characterized in that at some time before the working potential is applied and the concentration of the analyte is determined a potential significantly in excess of the working potential is applied, whereby to reduce the period required to establish a signal sufficiently stable to permit the determination to be effected.
Abstract: A flow through type ion electrode apparatus including a number of interconnectable block structures. Each block structure includes recesses in respective faces thereof, which lead to a through hole extending between the faces. A membrane electrode is located within each block structure so as to communicate with the through hole. A spacer having a through hole therein is inserted in a recess of each of a pair of adjacent block structures to interconnect the adjacent block structures.
Abstract: A modular multi-channel automated medical analyzer device is disclosed, characterized by use of an ion selective electrode and/or enzymatic electrode/wash cell system which permits rapid analysis of various substances of interest contained within undiluted body fluids such as whole blood, serum and/or plasma. The ion selective electrode and/or the enzymatic electrode are disposed upon a probe which automatically axially reciprocates downwardly in a simple manipulative motion between an open-ended reference wash cell and a sample cup bearing the body fluid specimen to be analyzed. The wash cell includes an inlet port and one or more outlet ports through which is circulated an aqueous solution bearing a known concentration of the substance to be measured to provide a reference calibration medium as well as a probe washing medium.
Type:
Grant
Filed:
November 15, 1985
Date of Patent:
June 19, 1990
Assignee:
SmithKline Diagnostics, Inc.
Inventors:
Max D. Liston, Paul K. Hsei, David G. Dickinson, George M. Daffern, James G. Fetty
Abstract: An apparatus for mounting a diffusion-limiting membrane for a sensor in which a mounting member for mounting a diffusion-limiting membrane holding plate is movable toward and away from an enzyme electrode unit and in which, with the mounting member positioned away from the enzyme electrode unit, a diffusion-limiting membrane holding plate having a diffusion-limiting membrane mounted thereon is mounted on or removed from the mounting member, thus preventing the diffusion-limiting membrane from being slidingly rubbed with the surface of the enzyme electrode and in which, with the holding plate mounted on the mounting member, the mounting member ius moved toward the enzyme electrode unit, causing the diffusion-limiting membrane to be stuck to the surface of the enzyme electrode unit.
Abstract: A composition for electroplating copper onto a conductive surface comprising a solution soluble copper salt and an acid electrolyte, said copper salt being present in a concentration of from about 1 to 10 grams per liter of solution and said acid being present in a concentration whereby the acid to copper ratio preferably varies between about 30 to 1 and 50 to 1. The composition is especially useful for the plating of walls of cylindrical openings having a ratio of height to diameter of at least 10 to 1 and a length of at least 0.100 inches.
Type:
Grant
Filed:
November 20, 1989
Date of Patent:
June 12, 1990
Assignee:
Shipley Company Inc.
Inventors:
Roger F. Bernards, Gordon Fisher, Wade Sonnenberg
Abstract: A process for electroplating copper from an aqueous alkaline non-cyanide bath has improved resistance to degradation. At least a portion of the plating bath is subjected to electrolysis by an insoluble anode to which the current is controlled independently from the current to the soluble copper anode in order to reduce the level of bath impurities and maintain the quality of the deposit.
Abstract: Ion-selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed. The ion carrier according to the invention is a lipophilic hemispherand compound. These compositions are particularly useful in ion-selective electrodes. Such an electrode is capable of selectively transporting a first ion in preference to a second ion. Particularly useful hemispherands have a .DELTA.G of complexation with the first ion which is at least 0.3 Kcal/mole greater than the .DELTA.G of complexation with the second ion. Dry-operative electrodes using these ion-selective compositions as membranes are also disclosed.
Abstract: This invention relates to fluoride ion-selective electrodes which employ, as the active membrane component, a ternary compound of the type M.sub.x Ln.sub.y F.sub.3-x, where M is an alkaline earth metal ion such as calcium, strontium or barium, and Ln is a lanthanide metal ion such as lanthanum, cerium, prosiodymium, neodymium, promethium, samarium and europium.
Abstract: A diffusion-limiting membrane holding means for a sensor comprising: a slender resilient thin plate, of which one shorter side serves as an engagement side, and of which one longer side is provided at its predetermined position with an engagement portion, an opening being formed in the thin plate between the engagement side and the engagement portion; and a diffusion-limiting membrane integrally attached to the thin plate as covering the opening; whereby the resliency of the thin plate causes the diffusion-limiting membrane to be stuck to the surface of an enzyme electrode unit of a sensor, thus enhancing the accuracy of concentration measurement of a target substance to be measured.
Abstract: A high pressure coulometric titration apparatus features a pressure vessel for containing a titration vessel, which is capable of being subjected to a pressure above the vaporization pressure of the sample to be analyzed. A back pressure regulator is employed to maintain the internal chamber created by the pressure vessel at this predetermined pressure level, so that the sample will remain in a liquid phase throughout the analysis. A fluid control arrangement is also provided for sweeping the chamber with a dry, inert gas, as well as conveying a predetermined amount of the sample to the titration vessel. This fluid control arrangement in combination with the pressure vessel operates to insure that all of the water in the sample will be trapped in the solvent, as well as to prevent the introduction of extraneous water into the system.
Type:
Grant
Filed:
July 7, 1989
Date of Patent:
May 29, 1990
Assignee:
The Dow Chemical Company
Inventors:
Frederick Simonson, III, Timothy M. Gunn
Abstract: Methods and apparatus for detecting immunochemical reactions and levels of antigens and antibodies in serum. A selected immunochemical reactant is bound to the surface of a first electrode. A second electrode is provided such that the electrodes generate a galvanic current when electrically interconnected and immersed in conductive aqueous solution. The electrodes are electrically interconnected and immersed into a conductive aqueous solution containing the complementary immunochemical reactant to the bound immunochemical reactant. The galvanic current generated by the immersed electrodes is measured as a function of time. The level of the complementary immunochemical reactant in the solution is calculated by comparing the measured current with a standard current.
Type:
Grant
Filed:
January 31, 1989
Date of Patent:
May 22, 1990
Assignee:
Board of Regents, The University of Texas
Inventors:
Christopher L. Reading, Malcolm R. Smyth, Richard O'Kennedy
Abstract: Disclosed is an enzyme sensor for measuring a predetermined substrate concentration by potentiometric or amperometric response on the basis of an enzyme. In one aspect, a solid-state enzyme sensor measures a predetermined substrate concentration by potentiometric response and includes a solid enzyme membrane-coated electrically conductive base, redox layer or ion-sensitive layer. In another aspect, a solid-state enzyme sensor measures a predetermined substrate concentration by amperometric response and includes a solid enzyme membrane-coated oxygen reduction catalyst layer. Also disclosed is an enzyme control layer for controlling the outflow and inflow of the enzyme layer.
Abstract: Novel chromium plating baths suitable for electrodepositing chromium layers which are bright, adherent, smooth and hard, and are capable of being formed at both high and low current densities, and at high cathodic current efficiencies, consist essentially of chromic acid and sulfoacetic acid in a concentration range of about 40 to 150 g/l., and selenate or tellurate ion. Sulfate ion, if present, is included in low concentrations such that the Cr/SO.sub.4 ratio is high, preferably 300:1 or more.