Patents by Inventor James E. Atwater

James E. Atwater 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).

  • Patent number: 6077478
    Abstract: A device and method for elimination of contamination during transfer of materials either into or from bioreactors, food containers, or other microbially vulnerable systems. Using microwave power, thermal sterilizations of mating fixtures are achieved simply, reliably, and quickly by the volatilization of small quantities of water to produce superheated steam which contacts all exposed surfaces.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: June 20, 2000
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Richard L. Sauer, James E. Atwater, Roger W. Dahl, Frank C. Garmon, Teddie D. Lunsford, William F. Michalek, Richard R. Wheeler, Jr.
  • Patent number: 5910448
    Abstract: The process of this invention comprises providing a membrane for separating CO.sub.2 into a first CO.sub.2 sample phase and a second CO.sub.2 analyte phase. CO.sub.2 is then transported through the membrane thereby separating the CO.sub.2 with the membrane into a first CO.sub.2 sample phase and a second CO.sub.2 analyte liquid phase including an ionized, conductive, dissociated CO.sub.2 species. Next, the concentration of the ionized, conductive, dissociated CO.sub.2 species in the second CO.sub.2 analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO.sub.2 to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO.sub.2 in the first CO.sub.2 sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO.sub.2 species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO.sub.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: June 8, 1999
    Assignee: Umpqua Research Company
    Inventors: James E. Atwater, James R. Akse, Jeffrey DeHart
  • Patent number: 5882937
    Abstract: Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: March 16, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Richard L. Sauer, James R. Akse, John O. Thompson, James E. Atwater
  • Patent number: 5792621
    Abstract: A "reagentless" chemiluminescent biosensor and method for the determination of hydrogen peroxide, ethanol and D-glucose in water. An aqueous stream is basified by passing it through a solid phase base bed. Luminol is then dissolved in the basified effluent at a controlled rate. Oxidation of the luminol is catalyzed by the target chemical to produce emitted light. The intensity of the emitted light is detected as a measure of the target chemical concentration in the aqueous stream. The emitted light can be transmitted by a fiber optic bundle to a remote location from the aqueous stream for a remote reading of the target chemical concentration.
    Type: Grant
    Filed: June 28, 1995
    Date of Patent: August 11, 1998
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Charles E. Verostko, James E. Atwater, James R. Akse, Jeffrey L. DeHart, Richard R. Wheeler
  • Patent number: 5643799
    Abstract: The process of this invention comprises providing a membrane for separating CO.sub.2 into a first CO.sub.2 sample phase and a second CO.sub.2 analyte phase. CO.sub.2 is then transported through the membrane thereby separating the CO.sub.2 with the membrane into a first CO.sub.2 sample phase and a second CO.sub.2 analyte liquid phase including an ionized, conductive, dissociated CO.sub.2 species. Next, the concentration of the ionized, conductive, dissociated CO.sub.2 species in the second CO.sub.2 analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO.sub.2 to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO.sub.2 in the first CO.sub.2 sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO.sub.2 species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO.sub.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: July 1, 1997
    Assignee: Umpqua Research Company
    Inventors: James E. Atwater, James R. Akse, Jeffrey DeHart