Patents by Inventor Yi-Han Kao

Yi-Han Kao 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: 5747425
    Abstract: High T.sub.c superconducting magnetic shields are provided, together with a method of fabricating such shields, wherein the shields exhibit very high critical applied magnetic field values of at least about 50 Gauss at 77 K. In fabrication procedures, a particulate superconducting ceramic oxide (24) (e.g., thallium 2223) is placed within an uniaxial die assembly (10) and subjected to compression while the die is heated via an external heating jacket (26). After formation of a self-sustaining body (24a), the die (10) is additionally heated via the jacket (26). External heating of the die (10) with the superconducting material therein reduces internal stresses within the shield body.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: May 5, 1998
    Assignee: Midwest Superconductivity Inc.
    Inventors: Ying Xin, Wangsong He, Michael S. P. Lucas, Xin Fei, Yi-Han Kao
  • Patent number: 5561102
    Abstract: A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: October 1, 1996
    Assignee: The Research Foundation of State University of New York at Buffalo
    Inventors: Yi-Han Kao, Liwei Song, Deborah D. L. Chung, Kevin T. Fredette
  • Patent number: 5470821
    Abstract: Composite bulk superconducting materials having desirable physical, measured transport current density and high T.sub.c superconducting characteristics are provided which comprise a first matrix of superconducting ceramic oxide crystalline grains with a second matrix of elemental metal (gold, silver, palladium and tin) situated within the interstices between the crystalline grains. Preferably, each matrix is a continuous phase within the composite material, with the ceramic oxide preferably being present at a level of at least about 80% by weight, whereas the elemental metal is present at a level of up to about 20% by weight. In fabrication procedures, a precursor superconducting ceramic oxide is first prepared and reduced to a fine powder size; this is mixed with powdered elemental metal, and the mixture is compressed using high compaction pressures on the order of 14 tons/cm.sup.2 or greater to form a body, which is then sintered to yield the composite.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: November 28, 1995
    Assignees: The University of Kansas, Midwest Superconductivity, Inc.
    Inventors: Kai W. Wong, Xin Fei, Ying Xin, Yi-Han Kao
  • Patent number: 5380703
    Abstract: A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting-a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: January 10, 1995
    Assignee: The Research Foundation of State University of New York at Buffalo
    Inventors: Yi-Han Kao, Liwei Song, Deborah D. L. Chung, Kevin T. Fredette
  • Patent number: 5329165
    Abstract: A selectively controllable, direction-, amplitude- and/or frequency-specific superconducting shield (10) is provided which includes a multiply-connected superconducting shield (12) adapted to shield a zone (13) from external magnetic, electric and/or electromagnetic fields and signals. Controlled gating of the shield (12) is provided by means (16) serving to selectively lower the critical shielding current density of a portion (26) of the shield (12) to a level permitting entrance of external fields through the portion (26), while leaving the critical shielding current densities of other portions of the shield (12) at higher, field-shielding levels. The means (16) preferably includes respective, selectively energizable coil pairs (CP.sub.1, CP.sub.2 . . . CP.sub.n) disposed about the shield (12). A highly sensitive magnetic detector (30) would include the shielding device (10) as well as a SQUID assembly (18) situated within the zone (13) defined by shield (12).
    Type: Grant
    Filed: May 26, 1992
    Date of Patent: July 12, 1994
    Assignee: Midwest Superconductivity, Inc.
    Inventors: Yi-Han Kao, Kai W. Wong