Patents by Inventor John A. Grisham

John A. Grisham 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: 20200215776
    Abstract: Systems and methods for embedding fiber optics cables within woven fibers. More specifically, protecting fiber optic cables from fluids, well pressure, mechanical strain, and environmental hazards within a downhole setting, wherein the fiber optic cables are protected using braided fibers, gel, and metals.
    Type: Application
    Filed: January 6, 2020
    Publication date: July 9, 2020
    Inventors: John Grisham, Neil Gardner
  • Publication number: 20050011199
    Abstract: A method, system, and apparatus for controlling the temperature within a remotely located enclosure that contains temperature sensitive equipment is provided. For some embodiments, the system includes an array of thermoelectric cooling (TEC) devices that act as an active cooling device and an active heating device. The system may also include a temperature controller that receives signals from a temperature sensor located at or near the temperature sensitive equipment. The controller may be configured to supply DC power to the thermoelectric coupling devices based on the output signal of the temperature sensor. The polarity of the DC power can be reversed by the controller in order to cause the thermoelectric device to heat or to cool the enclosure. The system also contains a passive cooling device. The system includes an independent electrical power source with a battery and solar cell to supply power to the temperature control devices and the equipment contained in the enclosure.
    Type: Application
    Filed: July 15, 2003
    Publication date: January 20, 2005
    Inventors: John Grisham, Michael Meadows, Leslie Perry, Alan Sallwasser
  • Patent number: 5907401
    Abstract: The device and method for performing an optical Hall test provide means for on-destructive measurement of free carrier concentration or effective mass in semiconductor materials using Faraday rotation spectra. A beam emitted by a Fourier transform infrared (FTIR) spectrometer is transmitted through the sample that is mounted between a polarizer and analyzer and the opposite poles of a magnet before finally being incident on a detector. The ratio of the samples's transmission spectrum with the magnetic field on to that with the magnetic field off is converted, through a suitable mathematical formula, to Faraday rotation. The rotation is, then, plotted versus the square of the wavelength. The slope of the graph at longer wavelengths is directly proportional to the carrier concentration and the effective mass. With one known, the other can be easily determined.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: May 25, 1999
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Frederick W. Clarke, Joseph K. McDonald, Charles R. Christensen, John A. Grisham
  • Patent number: 5210417
    Abstract: A modulated Faraday rotation signal is produced by passing a linearly polarized laser beam through a semiconductor wafer sample in a modulated magnetic field that is induced in an electromagnet by a sine wave generator and driver coupled thereto. The rotation signal is normalized by dividing by a transmission signal produced by modulating the beam with a chopper that operates at a different frequency from the frequency of the driver. The result is a Faraday rotation measurement with high signal-to-noise ratio and compensation for laser drift in intensity.
    Type: Grant
    Filed: February 24, 1992
    Date of Patent: May 11, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: John A. Grisham, Frederick W. Clarke, Charles R. Christensen, John L. Stensby
  • Patent number: 4818881
    Abstract: A sensitive infrared polarimeter that measures the amount of degree of rotation of the plane of polarization of plane polarized radiation after the radiation has passed through a wafer of cadmium sulfide. The wafer is placed in a relatively small magnetic field that is varied. Increased sensitivity is realized by using a chopping wheel to chop the laser beam, providing a reference frequency and by detecting the signals with a synchronous detector such as a lock-in amplifier to obtain high signal to noise ratios of the detected signal. The greater sensitivity of the high-sensitivity infrared polarimeter allows electronic carrier concentrations as low as 10.sup.15 cm.sup.-3 to be measured in cadmium sulfide with magnetic fields as low as 0.1 Tesla.
    Type: Grant
    Filed: May 4, 1987
    Date of Patent: April 4, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: George A. Tanton, John A. Grisham