Patents by Inventor Mark E. Burkhard

Mark E. Burkhard 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).

  • Means and method for hydraulically isolating unsaturated zones in soil
    Patent number: 5421672
    Abstract: A method and apparatus for hydraulically isolating a volume in porous unsaturated material, such as soil. Air is forced through a permeable layer of material adjacent to the volume to be hydraulically isolated. The air flow through the permeable layer creates a water potential gradient. This causes water to migrate from more saturated areas which in turn would allow hydraulic isolation of any unsaturated area.
    Type: Grant
    Filed: March 23, 1994
    Date of Patent: June 6, 1995
    Assignee: Daniel B. Stephens & Associates, Inc.
    Inventors: Mark D. Ankeny, Mark E. Burkhard