Patents by Inventor Digby D. MacDonald

Digby D. MacDonald has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040086648
    Abstract: A metal oxide layer can be deposited onto metallic or ceramic surfaces of a structure in situ, by exposing the surfaces to a precursor solution at an elevated temperature. The precursor solution contains: an organometallic, an oxidant, a surfactant, a chelating agent and water. The precursor solution is injected into the structure and maintained at a specific temperature, pH level and pressure for a predetermined period of time. The resulting in situ metal oxide layer is permanently bonded to the surface structure and does require post deposition heat treatment.
    Type: Application
    Filed: June 11, 2003
    Publication date: May 6, 2004
    Inventors: Xiangyang Zhou, Zhuang Fei Zhou, Serguei N. Lvov, Digby D. MacDonald
  • Patent number: 5238553
    Abstract: A reference electrode for use in measuring electrochemical corrosion potential and pH of, for example, water in a drum boiler at supercritical temperatures and which is corrosive includes an alumina or zirconia tube which is packed with a bulk solid electrolyte. The electrolyte consists of a mixture of silver chloride and glass in an optimally 2 to 4 weight ratio or glass particles with silver chloride precipitated around each particle. A solidified silver chloride electrode interfaces with the bulk electrolyte and has embedded in it a conductive silver electrode which provides the electrical contact. Use of the foregoing provides an immobilized solid electrolyte which displays stability and integrity as the temperature and pressure cycles between extremes.
    Type: Grant
    Filed: May 11, 1992
    Date of Patent: August 24, 1993
    Assignee: Electric Power Research Institute
    Inventors: Samson Hettiarachchi, Herking Song, Digby D. Macdonald
  • Patent number: 5132093
    Abstract: The present invention relates to a compound of the formula: ##STR1## wherein (a) A is independently selected from --SR.sup.1, --NR.sup.1 R.sup.2, --PR.sup.1 R.sup.2, --Si,R.sup.1 R.sup.2 R.sup.3, or --SnR.sup.1 R.sup.2 R.sup.3,R.sup.1, R.sup.2 and R.sup.3 are each independently selected from alkyl, cycloalkyl, alkylcycloalkyl, arylalkyl having from 1 to 20 carbon atoms or aryl, substituted aryl, or where R.sup.2 and R.sup.3 together form a heterocycle group, having from 4 to 20 carbon atoms, andn is an integer from 1 to 5;(b) Y is selected from a direct bond or --CR.sup.4 R.sup.5 --, wherein R.sup.4 and R.sup.5 are each independently selected from hydrogen, or alkyl group having 1 to 20 carbon atoms or R.sup.4 and R.sup.5 together form a cycloalkyl group having 4 to 20 carbon atoms;(c) Z is aryl or substituted aryl; and(d) X is halogen, sulfonate, carboxylate, phosphate, carbonate, sulfate, or MD.sub.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: July 21, 1992
    Assignee: SRI International
    Inventors: Samson Hettiarachchi, Subhash C. Narang, Digby D. Macdonald
  • Patent number: 5061581
    Abstract: An amorphous ionically conductive macromolecular solid is set forth having improved ambient temperature ionic conductivity. The solid comprises a solid solution of at least one positively charged ionic species dissolved in a macromolecular material, the macromolecular material comprising a polymer or copolymer having a polyether structure and having at least a portion of the ether oxygens thereof replaced with S or NR wherein R includes at least one basic site capable of associating with the positively charged ionic species and has 2 to 10 carbon atoms. Relatively high conductivity is a feature of the macromolecular solid of the invention.
    Type: Grant
    Filed: February 7, 1990
    Date of Patent: October 29, 1991
    Assignee: SRI International
    Inventors: Subhash C. Narang, Digby D. MacDonald
  • Patent number: 4406766
    Abstract: An electrode for measuring the pH of a liquid at high temperatures and pressures comprises a first hollow electrode formed of the ceramic which exhibits a pH-dependent potential thereacross and a second electrode provided with a porous ceramic junction. Two flexible-walled members are in fluid communication with the hollow interior of the two electrodes and are surrounded by a chamber whose pressure is kept substantially the same as that to which the electrodes are exposed. However, the chamber is thermally insulated from the hot solution whose pH is being measured. The interiors of the hollow electrodes and the flexible-walled members are filled with the same buffered solution and measuring electrodes are disposed within each of the flexible-walled members. The construction enables the measuring electrodes to be kept at substantially room temperature, thereby reducing chemical attack thereon and eliminates errors in potential measurement due to streaming and thermal diffusion potentials.
    Type: Grant
    Filed: October 13, 1981
    Date of Patent: September 27, 1983
    Assignee: The Ohio State University
    Inventor: Digby D. Macdonald
  • Patent number: 4273637
    Abstract: A system for measuring the potential between a working electrode in a pressurized, high temperature environment containing a solution which supports electrolytic conduction and a reference electrode is disclosed herein. This system utilizes an external reference electrode assembly which includes a particular technique of balancing its own internal pressure with the pressure in the high temperature environment in order to eliminate streaming potentials between the working electrode and the reference electrode. This assembly also includes a technique for maintaining the concentration of electrolytic solution at a substantially fixed and uniform level so as to maintain a fixed thermal liquid junction.
    Type: Grant
    Filed: January 23, 1980
    Date of Patent: June 16, 1981
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Digby D. MacDonald, Arthur C. Scott