Patents by Inventor Robert W. G. MacDonald

Robert W. G. 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).

  • Patent number: 6221262
    Abstract: Method for reducing the number of viable organisms present in ship ballast water wherein the ballast water is treated so as to reduce the concentration of dissolved oxygen and/or carbon dioxide to a level(s) at which a substantial portion of the organisms present cease to remain viable. The treatment comprises adding to the ballast water a suitable amount of an antioxidant.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: April 24, 2001
    Inventors: Robert W. G. MacDonald, Robert Bull, Douglas F Porter, Peter Lansell
  • Patent number: 5080481
    Abstract: A screen simulator window having a window aperture through which a scene may be viewed with a partial screen arranged immediately behind the window. The screen consists of alternately opaque screen portions and transparent screen portions. The adjacent screen portions are transposed at a speed such that the presence of the screen is not apparent to the eye of the viewer. A projector projects a scene onto rear sections of the opaque screen portions extending away from the window. A mirror behind the partial screen is viewable through the window. The scene projected onto the rear surface of the opaque screen portions is visible in the mirror and viewable through the window.
    Type: Grant
    Filed: January 29, 1990
    Date of Patent: January 14, 1992
    Assignee: Arnotts Biscuits Limited
    Inventors: Donald L. M. Martin, Keith W. Kanaar, Robert W. G. MacDonald
  • Patent number: 4238912
    Abstract: The invention relates to a modular roofing system having a plurality of tray modules wherein each module is capable of accommodating one or more solar collectors. Each adjacent or adjacent groups of modules are connected to each other and there is provided support means for supporting the plurality of tray modules.
    Type: Grant
    Filed: March 27, 1978
    Date of Patent: December 16, 1980
    Assignee: Solar Thermal Consultants Pty. Limited
    Inventor: Robert W. G. MacDonald