Patents by Inventor Pedro B. Macedo

Pedro B. Macedo 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: 5678236
    Abstract: In this invention radioactive or hazardous containing materials are vitrified in a melter having two or more chambers. Glass feed materials are added to the primary chamber of the melter and they are heated to a molten glass which is then transported to one or more secondary chambers where hazardous and/or radioactive containing materials are added and are encapsulated and/or melted. In addition, the non-plutonium part of a glass feed can be melted in a non-radioactive environment which permits contact operations and maintenance; no radioactive shielding; and a conventional off gas system-similar to commercial vitrification plants. The hot molten "clean" glass is directed into a radioactive containment such as a "glove box"; shielded "glove box"; or hot cell, or a combination of these. By delivering hot "clean" glass from a melter including non-radioactive materials, 90% of the off gases will be non-radioactive.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: October 14, 1997
    Assignees: Pedro Buarque De Macedo, Theodore Aaron Litovitz
    Inventors: Pedro B. Macedo, Ian L. Pegg, Hamid Hojaji, Robert K. Mohr, Marek Brandys
  • Patent number: 5340372
    Abstract: Material, such as, for example, sealed double bags of asbestos containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace. Gas bubbles released into the melt form a gas curtain which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material. The presence of the gas bubbles reduces the cross-section of the molten glass through which current passes, which in turn increases the electrical resistance of the glass melt and therefore increases power generation of the melt or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace. Drawn off glass is shaped and quenched into at least two sizes of approximate spheres. The spheres are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.
    Type: Grant
    Filed: June 29, 1992
    Date of Patent: August 23, 1994
    Assignees: Pedro Buarque de Macedo, Theodore Aaron Litovitz
    Inventors: Pedro B. Macedo, Robert K. Mohr
  • Patent number: 5188649
    Abstract: Material, such as, for example, sealed double bags of asbestos containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace. Gas bubbles released into the melt form a gas curtain which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material. The presence of the gas bubbles reduces the cross-section of the molten glass through which current passes, which in turn increases the electrical resistance of the glass melt and therefore increases power generation of the melt or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace. Drawn off glass is shaped and quenched into at least two sizes of approximate spheres. The spheres are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: February 23, 1993
    Assignees: Pedro Buarque de Macedo, Theodore Aaron Litovitz
    Inventors: Pedro B. Macedo, Robert K. Mohr
  • Patent number: 4902426
    Abstract: The present invention comprises a process for separating rare earth ions or actinide ions or mixtures thereof in solution by passing the solution through an ion exchange material to separate the rare earths or actinides or mixtures thereof. The ion exchange material has a surface area of about 5-1500 m.sup.2 /g. The ion exchange material is impregnated with a liquid containing alkali metal cations, Group Ib metal cations, ammonium cations, organic amines or mixtures thereof, at a pH range above about 9. A plurality of fractions of the solution is collected as the solution passes through the ion exchange material, preferably in a column. This process is particularly preferred for separating rare earth ions and especially lanthanum and neodymium. It is particularly preferred to purify lanthanum to contain less than 0.1 ppm, preferably less than 0.01 ppm, of neodymium.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: February 20, 1990
    Assignees: Pedro B. Macedo, Theodore Aaron Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Hamid Hojaj
  • Patent number: 4737316
    Abstract: A liquid containing radioactive ions is purified (decontaminated) by contacting the same with an inorganic ion exchange composition having ion exchange sites which can be occupied by the radioactive ions from the liquid. The ion exchange composition is a mixture of an ion exchange medium and an additive which is relatively inert to the ion exchange process and which is a sintering aid for the ion exchange medium designed to lower the sintering temperature of the ion exchange composition. The ion exchange composition may be disposed within a suitable container (e.g., cannister), e.g., made of 304L stainless steel or Inconel 601 and the ion exchange process may be carried out in such container. Alternatively, the ion exchange medium can be employed without being previously admixed with the additive. The additive, if desired, can be admixed at a later stage with the contaminated medium.
    Type: Grant
    Filed: May 20, 1986
    Date of Patent: April 12, 1988
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Herbert G. Sutter, Robert K. Mohr, Catherine J. Simmons
  • Patent number: 4687581
    Abstract: A method for separating and purifying cations by ion exchange with regenerable porous glass. More specifically, the method is for decontaminating toxic waste streams such as a radioactive waste streams and concentrating the radioactive cations contained therein which comprises passage of the waste stream through an ion exchange medium of porous silicate glass or silica gel. In one embodiment, a liquid nuclear waste stream is passed through an ion exchange column containing porous silicate glass or silica gel having a plurality of .tbd.Si--O--Z groups wherein Z represents a non-radioactive cation (hydrogen, alkali metals, Group Ib metals and ammonium cations, and mixtures thereof) to displace the non-radioactive cations of the silicate glass or silica gel by the radioactive cations of the waste stream. Thereafter, the ion exchange medium is contacted with an aqueous solution of an acid to strip the radioactive cations therefrom and the stripped ion exchange medium is regenerated.
    Type: Grant
    Filed: January 30, 1984
    Date of Patent: August 18, 1987
    Assignee: Pedro B. Macedo
    Inventors: Pedro B. Macedo, Aaron Barkatt, Herbert G. Sutter
  • Patent number: 4659512
    Abstract: A process for removing metal species from solution comprising passing the liquid over a composition comprising a support such as a porous silicate glass or silica gel or charcoal having interconnected pores and containing water soluble amine complexing agents absorbed on the support capable of forming a stable complex with the metal species. The preferred amine complexing agent is triethylenetetramine. The process is especially useful for removing radioactive cobalt from liquid waste streams.
    Type: Grant
    Filed: December 21, 1983
    Date of Patent: April 21, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Aaron Barkatt
  • Patent number: 4659477
    Abstract: A composition comprising a support such as a porous silicate glass or silica gel or charcoal having interconnected pores and containing heavy metal cations of mercury, thallium, silver, platinum, palladium, lead or copper capable of forming a stable complex with an anion bonded to the support. The preferred heavy metal cation is a mercury cation. The composition is especially useful for removing radioactive iodine from liquid and gaseous waste streams.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: April 21, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Aaron Barkatt
  • Patent number: 4654146
    Abstract: A process for removing heavy alkali metal cations from solution comprising passing a liquid over a composition including a support such as charcoal having interconnected pores containing a tetra-aryl boron moiety associated with an ion exchangeable cation absorbed on the support capable of forming a stable compound with a heavy alkali metal cation.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: March 31, 1987
    Assignees: Pedro B. Macedo, Theodore Aaron Litovitz
    Inventors: Aaron Barkatt, Pedro B. Macedo
  • Patent number: 4648975
    Abstract: Silica-based chromatographic and reactive materials are disclosed with surfaces modified to contain or to be coated with oxides, hydrous oxides, hydroxides, carbonates or silicates of aluminum, iron, or other suitable metals such as zirconium or titanium. The materials exhibit good resistance to dissolution and resulting loss of activity or clogging. This good resistance is particularly evident even in the high pH region (above 8-9) and in the high temperature region (above 35.degree. C.) where the dissolution rates and solubilities of aluminosilicates and of trivalent iron oxides are much smaller than those of silica.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: March 10, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Aaron Barkatt, Pedro B. Macedo
  • Patent number: 4591455
    Abstract: A liquid containing radioactive ions is purified (decontaminated) by contacting the same with an inorganic ion exchange composition having ion exchange sites which can be occupied by the radioactive ions from the liquid. The ion exchange composition is a mixture of an ion exchange medium and an additive which is relatively inert to the ion exchange process and which is a sintering aid for the ion exchange medium designed to lower the sintering temperature of the ion exchange composition. The ion exchange composition may be disposed within a suitable container (e.g., cannister), e.g., made of 304L stainless steel or Inconel 601 and the ion exchange process may be carried out in such container. Alternatively, the ion exchange medium can be employed without being previously admixed with the additive. The additive, if desired, can be admixed at a later stage with the contaminated medium.
    Type: Grant
    Filed: November 24, 1982
    Date of Patent: May 27, 1986
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Herbert G. Sutter, Robert K. Mohr, Catherine J. Simmons
  • Patent number: 4552577
    Abstract: The present invention is directed to a method and apparatus for forming shaped foamed-glass articles. Glass particles are introduced to a pressure vessel in the presence of water. A pressure is applied to the pressure vessel sufficient to permit entrapment of water during sintering and sufficient to prevent foaming at processing temperatures. The temperature of the glass is increased to cause the glass to sinter and entrap water. The temperature of the glass is then increased to its fining temperature (T.sub.F) for a sufficient time to fine the glass. The temperature of the glass is reduced to its pressure release temperature (T.sub.PR). The pressure on the glass containing water is then reduced such as by extrusion to cause controlled foaming of the glass to occur. The glass is then cooled preferably by annealing to form the shaped foamed-glass article, typically pipe insulation.
    Type: Grant
    Filed: April 5, 1983
    Date of Patent: November 12, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Deepak Varshneya, Pedro B. Macedo, Robert K. Mohr
  • Patent number: 4544499
    Abstract: This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal.
    Type: Grant
    Filed: June 7, 1982
    Date of Patent: October 1, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Danh C. Tran, Pedro B. Macedo, Joseph H. Simmons, Catherine J. Simmons, Nicholas Lagakos
  • Patent number: 4528011
    Abstract: This invention relates to the immobilization of toxic materials, e.g., radioactive materials, in glass for extremely long periods of time. Toxic materials, such as radioactive wastes, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are deposited in a glass container which is heated to evaporate off non-radioactive volatile materials, if present; to decompose salts, such as nitrates, if any, and to drive off volatile non-radioactive decomposition products, and then to collapse the walls of said container on said radwaste and seal the container and immobilize the contained radwaste, and then burying the resulting product underground or at sea. In another embodiment, the glass container also contains glass particles, e.g., spheres or granules, on which the radwaste solids are deposited.
    Type: Grant
    Filed: December 14, 1981
    Date of Patent: July 9, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Catherine J. Simmons, Danh C. Tran, Nicholas Lagakos, Joseph Simmons
  • Patent number: 4469628
    Abstract: This invention relates to the immobilization of toxic, e.g., radioactive, materials in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are incorporated into a glass or silica gel matrix, having alkali metal, Group Ib metal and/or ammonium cations bonded to silicon atoms of said glass or silica gel through divalent oxygen linkages, by a process which involves the ion exchange of said toxic or radioactive cations with said alkali metal, Group Ib metal and/or ammonium cations to bind said toxic or radioactive cations to silicon atoms of said glass or silica gel through said silicon-bonded divalent oxygen linkages.
    Type: Grant
    Filed: April 21, 1982
    Date of Patent: September 4, 1984
    Inventors: Catherine J. Simmons, Joseph H. Simmons, Pedro B. Macedo, Theodore A. Litovitz
  • Patent number: 4443700
    Abstract: A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical waveguide, preferably an optical fiber waveguide, a light source which injects light into one end of the waveguide, a deformer contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector to detect the change in light coupling caused by deformation of the waveguide.
    Type: Grant
    Filed: May 13, 1982
    Date of Patent: April 17, 1984
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Nicholas Lagakos, Robert K. Mohr, Robert Meister
  • Patent number: 4362659
    Abstract: This invention relates to radioactive materials which are fixed, stored, entrapped, encapsulated, or otherwise rendered immobile in a glass matrix for extremely long periods of time. Radioactive material such as radioactive wastes are incorporated into a glass matrix by a process of "molecular stuffing" a porous glass either with a radioactive gas which is tapered in the porous glass by dissolution during sintering of the pores of the glass, or with a salt solution containing radioactive material such as CsNO.sub.3, Sr(NO.sub.3), etc., or with a combination of both salt solution and radioactive gas, followed by drying and sintering of the pores of the glass whereby these radioactive materials upon chemical change to their oxides, excepting of course the noble gases which remain in molecular form, become a part of the integrated glass structure.
    Type: Grant
    Filed: September 17, 1979
    Date of Patent: December 7, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Joseph H. Simmons, Theodore A. Litovitz
  • Patent number: 4362542
    Abstract: In a method of making a strong fiber waveguide in which a preform is heated and pulled to make the fiber, the improvement includes adding to the preform at least one dopant capable of creating a mechanical stress profile in the preform and at least another dopant capable of creating an index of refraction profile in the preform, and varying the dopants added to produce a composition profile so that the composition profile varies radially from the center to the surface to form a core, an intermediate clad layer having an index of refraction lower than the core, and a surface layer which is in compression having a thermal expansion coefficient smaller than the core and having a predetermined thickness less than 10% of the radius of the core, the compression being greater than 20,000 psig.
    Type: Grant
    Filed: November 2, 1981
    Date of Patent: December 7, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Robert K . Mohr, Prabhat K. Gupta
  • Patent number: 4342907
    Abstract: A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical waveguide, preferably an optical fiber waveguide, a light source which injects light into one end of the waveguide, a deformer contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector to detect the change in light coupling caused by deformation of the waveguide.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: August 3, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Nicholas Lagakos, Robert K. Mohr, Robert Meister
  • Patent number: 4333847
    Abstract: This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: June 8, 1982
    Assignees: P. B. Macedo, T. A. Litovitz
    Inventors: Danh C. Tran, Pedro B. Macedo, Joseph H. Simmons, Catherine J. Simmons, Nicholas Lagakos